Re: [PATCH 2/2] USB: hub: change the locking in hub_activate

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05-08-16, 11:51, Alan Stern wrote:
> +++ usb-4.x/drivers/usb/core/hub.c
> @@ -1052,7 +1052,7 @@ static void hub_activate(struct usb_hub
>  
>  	/* Continue a partial initialization */
>  	if (type == HUB_INIT2 || type == HUB_INIT3) {
> -		device_lock(hub->intfdev);
> +		device_lock(&hdev->dev);

Hi Alan,

I have received reports of kernel crashes (NULL dereference) due to this patch
in some of the corner cases. Note that we have backported this patch (and few
other) to 3.10 kernel. I have attached my hub.c file as well for reference.

Here is the reported kernel OOPs:

[   19.476228] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   19.476231] pgd = ffffffc00007d000
[   19.476236] [00000000] *pgd=000000000e90b003, *pmd=000000000e90c003, *pte=00e00000f9000407
[   19.476242] Internal error: Oops: 96000045 [#1] PREEMPT SMP
[   19.476273] Modules linked in: gb_vibrator(O) gb_usb(O) gb_uart(O) gb_spi(O) gb_sdio(O) gb_raw(O) gb_pwm(O) gb_power_supply(O) gb)
[   19.476279] CPU: 0 PID: 344 Comm: kworker/0:3 Tainted: G           O 3.10.97-g4b7224f-dirty #454
[   19.476290] Workqueue: events hub_init_func2
[   19.476293] task: ffffffc09b3560c0 ti: ffffffc09ada8000 task.ti: ffffffc09ada8000
[   19.476300] PC is at __mutex_lock_slowpath+0x138/0x224
[   19.476303] LR is at __mutex_lock_slowpath+0x128/0x224
[   19.476306] pc : [<ffffffc000ccf13c>] lr : [<ffffffc000ccf12c>] pstate: 80000145
[   19.476307] sp : ffffffc09adabc30
[   19.476310] x29: ffffffc09adabc30 x28: 0000000000000000
[   19.476313] x27: ffffffc001753a30 x26: 0000000000000000
[   19.476317] x25: ffffffc09b3560c0 x24: ffffffc09a4bd8f0
[   19.476320] x23: ffffffc09a4bd8ec x22: ffffffc0017cd000
[   19.476323] x21: ffffffc09adabc90 x20: ffffffc09ada8000
[   19.476326] x19: ffffffc09a4bd8e8 x18: ffffffc000e4f000
[   19.476329] x17: 0000000000000001 x16: 0000000000000007
[   19.476332] x15: 000000000000000e x14: 0ffffffffffffffe
[   19.476335] x13: 0000000000000030 x12: 0101010101010101
[   19.476338] x11: 7f7f7f7f7f7f7f7f x10: feff676273687672
[   19.476341] x9 : ffffffc09adabb90 x8 : ffffffc09b356620
[   19.476344] x7 : 00000000000001c0 x6 : ffffffc00160f698
[   19.476347] x5 : 0000000000000000 x4 : 0000000000000000
[   19.476350] x3 : ffffffc09adabc90 x2 : 0000000000000000
[   19.476353] x1 : 0000000000000000 x0 : 0000000000000000
[   19.476355]
[   19.476355] PC: 0xffffffc000ccf03c:
[   19.476365] f038  f9400a99a9046bf9 97d5b45797d5f351 52800037f9400e75 b9402ab7b4000055 910183b597d5b4d0 91008277340005f7 aa1703e051
[   19.476373] f078  b400013af9400e7a aa1a03e1aa1303e0 350000a097d5cbe3 aa1503e1aa1703e0 1400002097d5cbcc 7100041fb9400260 d5033bbf5b
[   19.476382] f0b8  88007e7854000061 d5033bbf35ffff80 540001017100077f aa1503e1f9400a80 aa1703e0f9000e60 2a1b03e097d5cbba aa1703e011
[   19.476390] f0f8  f9400280b50000da b9403320370800e0 5400008d71018c1f 97ddbd2fd28218e0 9100127717ffffd5 aa1703e091002278 f90033b890
[   19.476398] f138  f9000015f9000715 b9400260f9003bb9 9280001536f80080 14000015d280005a 885f7e6192800000 35ffffc28802fe60 7100043fd1
[   19.476407] f178  8801fe75885f7e60 d5033bbf35ffffc1 540001407100041f f900033aaa1703e0 9400073494000af1 94000a43aa1703e0 36fffe60b8
[   19.476415] f1b8  f9000420f94037a0 f9400a80f9000001 f9400660f9000e60 54000041eb18001f aa1703e0b900027f 5280002094000adf f940028090
[   19.476424] f1f8  f94096c0f9403fa1 54000040eb00003f a94153f397d54136 a94363f7a9425bf5 f9402bfba9446bf9 d65f03c0a8c87bfd 910003fda3
[   19.476432] f238  51000421885f7c01 35ffffa28802fc01 36f80041d5033bbf 910003e097ffff6d f94008009272c400 f9400bf3f9000e60 d65f03c0ad
[   19.476434]
[   19.476434] LR: 0xffffffc000ccf02c:
[   19.476442] f028  9272c414910003e0 a90363f752800020 f9400a99a9046bf9 97d5b45797d5f351 52800037f9400e75 b9402ab7b4000055 910183b597
[   19.476450] f068  aa1703e052800018 97d5cbc5aa1503e1 b400013af9400e7a aa1a03e1aa1303e0 350000a097d5cbe3 aa1503e1aa1703e0 1400002090
[   19.476459] f0a8  d5033bbf54000221 7100077f885f7e7b 88007e7854000061 d5033bbf35ffff80 540001017100077f aa1503e1f9400a80 aa1703e0fa
[   19.476467] f0e8  aa1703e014000040 97d5cbb5aa1503e1 f9400280b50000da b9403320370800e0 5400008d71018c1f 97ddbd2fd28218e0 9100127718
[   19.476475] f128  f90033b894000a62 f90037a0f9400700 f9000015f9000715 b9400260f9003bb9 9280001536f80080 14000015d280005a 885f7e6190
[   19.476483] f168  7100043fd5033bbf 1400001054fffee1 8801fe75885f7e60 d5033bbf35ffffc1 540001407100041f f900033aaa1703e0 9400073490
[   19.476492] f1a8  36fffe60b9400260 f94033a117fffff8 f9000420f94037a0 f9400a80f9000001 f9400660f9000e60 54000041eb18001f aa1703e0bf
[   19.476500] f1e8  f940028097d5f318 940006dc36080040 f94096c0f9403fa1 54000040eb00003f a94153f397d54136 a94363f7a9425bf5 f9402bfbad
[   19.476508] f228  910003fda9be7bfd aa0003f3f9000bf3 51000421885f7c01 35ffffa28802fc01 36f80041d5033bbf 910003e097ffff6d f940080090
[   19.476510]
[   19.476510] SP: 0xffffffc09adabb30:
[   19.476518] bb30  0000000000000000 0000000000000000 ffffffc00160f698 00000000000001c0 ffffffc09b356620 ffffffc09adabb90 feff67627f
[   19.476527] bb70  0101010101010101 0000000000000030 0ffffffffffffffe 000000000000000e 0000000000000007 0000000000000001 ffffffc008
[   19.476535] bbb0  ffffffc09ada8000 ffffffc09adabc90 ffffffc0017cd000 ffffffc09a4bd8ec ffffffc09a4bd8f0 ffffffc09b3560c0 0000000000
[   19.476544] bbf0  0000000000000000 ffffffc09adabc30 ffffffc000ccf12c ffffffc09adabc30 ffffffc000ccf13c 0000000080000145 ffffffc098
[   19.476552] bc30  ffffffc09adabcb0 ffffffc000ccf254 ffffffc09a4bd8e8 ffffffc08ff36d90 ffffffc09a4bd800 0000000000000000 0000000000
[   19.476560] bc70  ffffffc001753a80 0000000000000000 ffffffc001753a30 ffffffc09b5b8ac0 ffffffc09a4bd8f0 0000000000000000 ffffffc00b
[   19.476569] bcb0  ffffffc09adabce0 ffffffc0006f6eac ffffffc08ff36c00 ffffffc000237fec 0000000000000140 ffffffc00e952400 ffffffc098
[   19.476577] bcf0  ffffffc09b375c80 ffffffc08ff36d90 ffffffc0ac13f3c0 0000000000000000 ffffffc0ac144700 ffffffc09ada8000 ffffffc000
[   19.476578]
[   19.476580] Process kworker/0:3 (pid: 344, stack limit = 0xffffffc09ada8058)
[   19.476582] Call trace:
[   19.476586] [<ffffffc000ccf13c>] __mutex_lock_slowpath+0x138/0x224
[   19.476590] [<ffffffc000ccf254>] mutex_lock+0x2c/0x48
[   19.476593] [<ffffffc0006f6eac>] hub_activate+0x50/0x4d8
[   19.476596] [<ffffffc0006f7388>] hub_init_func2+0x14/0x1c
[   19.476602] [<ffffffc0002387ac>] process_one_work+0x26c/0x3cc
[   19.476605] [<ffffffc000239988>] worker_thread+0x208/0x358
[   19.476610] [<ffffffc00023f360>] kthread+0xbc/0xc4
[   19.476614] Code: f90033b8 f9400700 f90037a0 f9000715 (f9000015)
[   19.476675] ---[ end trace fe479a523e72d286 ]---
[   19.480809] Kernel panic - not syncing: Fatal exception
[   19.480815] CPU5: stopping
[   19.480817]
[   19.480825] CPU: 5 PID: 1146 Comm: vold Tainted: G      D    O 3.10.97-g4b7224f-dirty #454
[   19.480829] task: ffffffc0922a0ac0 ti: ffffffc0922c8000 task.ti: ffffffc0922c8000
[   19.480841] PC is at 0x556cd66dd0
[   19.480845] LR is at 0x6b967265
[   19.480849] pc : [<000000556cd66dd0>] lr : [<000000006b967265>] pstate: 80000000
[   19.480851] sp : 0000007841cfee00
[   19.480858] x29: 0000007841cfeee0 x28: 0000000000000002
[   19.480864] x27: 0000000041c22ab2 x26: 00000000f479b30f
[   19.480870] x25: 000000004a0a4e1b x24: 0000000027828df0
[   19.480874] x23: 0000000004803c5f x22: 00000000a54bc039
[   19.480879] x21: 0000000054fb7083 x20: 00000000ba085058
[   19.480883] x19: 00000000c10eef4c x18: 00000000daf86b2b
[   19.480887] x17: 00000000f0416c8d x16: 000000784227dcc0
[   19.480892] x15: 0000007841cfee50 x14: 0000007841cfee48
[   19.480896] x13: 0000007841cfee0b x12: 0000007841cfee01
[   19.480900] x11: 0000007841cfee00 x10: 0000000000000003
[   19.480905] x9 : 0000000000000010 x8 : 000000000b706b41
[   19.480909] x7 : 000000002987d134 x6 : 0000000059360b19
[   19.480913] x5 : 00000000d4c87a5a x4 : 00000000aa878319
[   19.480917] x3 : 000000000672520c x2 : 0000000000000008
[   19.480921] x1 : 000000784227dc00 x0 : 000000784227d800
[   19.480923]
[   19.480928] CPU: 5 PID: 1146 Comm: vold Tainted: G      D    O 3.10.97-g4b7224f-dirty #454
[   19.480931] Call trace:
[   19.480942] [<ffffffc000207b5c>] dump_backtrace+0x0/0x268
[   19.480948] [<ffffffc000207dd8>] show_stack+0x14/0x1c
[   19.480955] [<ffffffc000cc8894>] dump_stack+0x20/0x28
[   19.480961] [<ffffffc00020efa0>] handle_IPI+0x170/0x2d0
[   19.480967] [<ffffffc000200790>] gic_handle_irq+0x70/0x84
[   19.480971] Exception stack(0xffffffc0922cbeb0 to 0xffffffc0922cbfd0)

This happens when the device is infinitely generating connected and then removed
(not manually, but due to some hardware issues).

-- 
viresh
/*
 * USB hub driver.
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999 Johannes Erdfelt
 * (C) Copyright 1999 Gregory P. Smith
 * (C) Copyright 2001 Brad Hards (bhards@xxxxxxxxxxxxxx)
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/usb/hcd.h>
#include <linux/usb/otg.h>
#include <linux/usb/quirks.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/random.h>
#include <linux/pm_qos.h>

#include <asm/uaccess.h>
#include <asm/byteorder.h>

#include "hub.h"

/* if we are in debug mode, always announce new devices */
#ifdef DEBUG
#ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
#define CONFIG_USB_ANNOUNCE_NEW_DEVICES
#endif
#endif

#define USB_VENDOR_GENESYS_LOGIC		0x05e3
#define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01

static inline int hub_is_superspeed(struct usb_device *hdev)
{
	return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS);
}

/* Protect struct usb_device->state and ->children members
 * Note: Both are also protected by ->dev.sem, except that ->state can
 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
static DEFINE_SPINLOCK(device_state_lock);

/* khubd's worklist and its lock */
static DEFINE_SPINLOCK(hub_event_lock);
static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */

/* Wakes up khubd */
static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);

static struct task_struct *khubd_task;

/* cycle leds on hubs that aren't blinking for attention */
static bool blinkenlights = 0;
module_param (blinkenlights, bool, S_IRUGO);
MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");

/*
 * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
 * 10 seconds to send reply for the initial 64-byte descriptor request.
 */
/* define initial 64-byte descriptor request timeout in milliseconds */
static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(initial_descriptor_timeout,
		"initial 64-byte descriptor request timeout in milliseconds "
		"(default 5000 - 5.0 seconds)");

/*
 * As of 2.6.10 we introduce a new USB device initialization scheme which
 * closely resembles the way Windows works.  Hopefully it will be compatible
 * with a wider range of devices than the old scheme.  However some previously
 * working devices may start giving rise to "device not accepting address"
 * errors; if that happens the user can try the old scheme by adjusting the
 * following module parameters.
 *
 * For maximum flexibility there are two boolean parameters to control the
 * hub driver's behavior.  On the first initialization attempt, if the
 * "old_scheme_first" parameter is set then the old scheme will be used,
 * otherwise the new scheme is used.  If that fails and "use_both_schemes"
 * is set, then the driver will make another attempt, using the other scheme.
 */
static bool old_scheme_first = 0;
module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(old_scheme_first,
		 "start with the old device initialization scheme");

static bool use_both_schemes = 1;
module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(use_both_schemes,
		"try the other device initialization scheme if the "
		"first one fails");

/* Mutual exclusion for EHCI CF initialization.  This interferes with
 * port reset on some companion controllers.
 */
DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);

#define HUB_DEBOUNCE_TIMEOUT	2000
#define HUB_DEBOUNCE_STEP	  25
#define HUB_DEBOUNCE_STABLE	 100

static int usb_reset_and_verify_device(struct usb_device *udev);

static inline char *portspeed(struct usb_hub *hub, int portstatus)
{
	if (hub_is_superspeed(hub->hdev))
		return "5.0 Gb/s";
	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
    		return "480 Mb/s";
	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
		return "1.5 Mb/s";
	else
		return "12 Mb/s";
}

/* Note that hdev or one of its children must be locked! */
struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
{
	if (!hdev || !hdev->actconfig || !hdev->maxchild)
		return NULL;
	return usb_get_intfdata(hdev->actconfig->interface[0]);
}

static int usb_device_supports_lpm(struct usb_device *udev)
{
	/* Some devices have trouble with LPM */
	if (udev->quirks & USB_QUIRK_NO_LPM)
		return 0;

	/* USB 2.1 (and greater) devices indicate LPM support through
	 * their USB 2.0 Extended Capabilities BOS descriptor.
	 */
	if (udev->speed == USB_SPEED_HIGH) {
		if (udev->bos->ext_cap &&
			(USB_LPM_SUPPORT &
			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
			return 1;
		return 0;
	}

	/* All USB 3.0 must support LPM, but we need their max exit latency
	 * information from the SuperSpeed Extended Capabilities BOS descriptor.
	 */
	if (!udev->bos->ss_cap) {
		dev_warn(&udev->dev, "No LPM exit latency info found.  "
				"Power management will be impacted.\n");
		return 0;
	}
	if (udev->parent->lpm_capable)
		return 1;

	dev_warn(&udev->dev, "Parent hub missing LPM exit latency info.  "
			"Power management will be impacted.\n");
	return 0;
}

/*
 * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
 * either U1 or U2.
 */
static void usb_set_lpm_mel(struct usb_device *udev,
		struct usb3_lpm_parameters *udev_lpm_params,
		unsigned int udev_exit_latency,
		struct usb_hub *hub,
		struct usb3_lpm_parameters *hub_lpm_params,
		unsigned int hub_exit_latency)
{
	unsigned int total_mel;
	unsigned int device_mel;
	unsigned int hub_mel;

	/*
	 * Calculate the time it takes to transition all links from the roothub
	 * to the parent hub into U0.  The parent hub must then decode the
	 * packet (hub header decode latency) to figure out which port it was
	 * bound for.
	 *
	 * The Hub Header decode latency is expressed in 0.1us intervals (0x1
	 * means 0.1us).  Multiply that by 100 to get nanoseconds.
	 */
	total_mel = hub_lpm_params->mel +
		(hub->descriptor->u.ss.bHubHdrDecLat * 100);

	/*
	 * How long will it take to transition the downstream hub's port into
	 * U0?  The greater of either the hub exit latency or the device exit
	 * latency.
	 *
	 * The BOS U1/U2 exit latencies are expressed in 1us intervals.
	 * Multiply that by 1000 to get nanoseconds.
	 */
	device_mel = udev_exit_latency * 1000;
	hub_mel = hub_exit_latency * 1000;
	if (device_mel > hub_mel)
		total_mel += device_mel;
	else
		total_mel += hub_mel;

	udev_lpm_params->mel = total_mel;
}

/*
 * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
 * a transition from either U1 or U2.
 */
static void usb_set_lpm_pel(struct usb_device *udev,
		struct usb3_lpm_parameters *udev_lpm_params,
		unsigned int udev_exit_latency,
		struct usb_hub *hub,
		struct usb3_lpm_parameters *hub_lpm_params,
		unsigned int hub_exit_latency,
		unsigned int port_to_port_exit_latency)
{
	unsigned int first_link_pel;
	unsigned int hub_pel;

	/*
	 * First, the device sends an LFPS to transition the link between the
	 * device and the parent hub into U0.  The exit latency is the bigger of
	 * the device exit latency or the hub exit latency.
	 */
	if (udev_exit_latency > hub_exit_latency)
		first_link_pel = udev_exit_latency * 1000;
	else
		first_link_pel = hub_exit_latency * 1000;

	/*
	 * When the hub starts to receive the LFPS, there is a slight delay for
	 * it to figure out that one of the ports is sending an LFPS.  Then it
	 * will forward the LFPS to its upstream link.  The exit latency is the
	 * delay, plus the PEL that we calculated for this hub.
	 */
	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;

	/*
	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
	 * is the greater of the two exit latencies.
	 */
	if (first_link_pel > hub_pel)
		udev_lpm_params->pel = first_link_pel;
	else
		udev_lpm_params->pel = hub_pel;
}

/*
 * Set the System Exit Latency (SEL) to indicate the total worst-case time from
 * when a device initiates a transition to U0, until when it will receive the
 * first packet from the host controller.
 *
 * Section C.1.5.1 describes the four components to this:
 *  - t1: device PEL
 *  - t2: time for the ERDY to make it from the device to the host.
 *  - t3: a host-specific delay to process the ERDY.
 *  - t4: time for the packet to make it from the host to the device.
 *
 * t3 is specific to both the xHCI host and the platform the host is integrated
 * into.  The Intel HW folks have said it's negligible, FIXME if a different
 * vendor says otherwise.
 */
static void usb_set_lpm_sel(struct usb_device *udev,
		struct usb3_lpm_parameters *udev_lpm_params)
{
	struct usb_device *parent;
	unsigned int num_hubs;
	unsigned int total_sel;

	/* t1 = device PEL */
	total_sel = udev_lpm_params->pel;
	/* How many external hubs are in between the device & the root port. */
	for (parent = udev->parent, num_hubs = 0; parent->parent;
			parent = parent->parent)
		num_hubs++;
	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
	if (num_hubs > 0)
		total_sel += 2100 + 250 * (num_hubs - 1);

	/* t4 = 250ns * num_hubs */
	total_sel += 250 * num_hubs;

	udev_lpm_params->sel = total_sel;
}

static void usb_set_lpm_parameters(struct usb_device *udev)
{
	struct usb_hub *hub;
	unsigned int port_to_port_delay;
	unsigned int udev_u1_del;
	unsigned int udev_u2_del;
	unsigned int hub_u1_del;
	unsigned int hub_u2_del;

	if (!udev->lpm_capable || udev->speed != USB_SPEED_SUPER)
		return;

	hub = usb_hub_to_struct_hub(udev->parent);
	/* It doesn't take time to transition the roothub into U0, since it
	 * doesn't have an upstream link.
	 */
	if (!hub)
		return;

	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
	udev_u2_del = udev->bos->ss_cap->bU2DevExitLat;
	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
	hub_u2_del = udev->parent->bos->ss_cap->bU2DevExitLat;

	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
			hub, &udev->parent->u1_params, hub_u1_del);

	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
			hub, &udev->parent->u2_params, hub_u2_del);

	/*
	 * Appendix C, section C.2.2.2, says that there is a slight delay from
	 * when the parent hub notices the downstream port is trying to
	 * transition to U0 to when the hub initiates a U0 transition on its
	 * upstream port.  The section says the delays are tPort2PortU1EL and
	 * tPort2PortU2EL, but it doesn't define what they are.
	 *
	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
	 * about the same delays.  Use the maximum delay calculations from those
	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
	 * assume the device exit latencies they are talking about are the hub
	 * exit latencies.
	 *
	 * What do we do if the U2 exit latency is less than the U1 exit
	 * latency?  It's possible, although not likely...
	 */
	port_to_port_delay = 1;

	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
			hub, &udev->parent->u1_params, hub_u1_del,
			port_to_port_delay);

	if (hub_u2_del > hub_u1_del)
		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
	else
		port_to_port_delay = 1 + hub_u1_del;

	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
			hub, &udev->parent->u2_params, hub_u2_del,
			port_to_port_delay);

	/* Now that we've got PEL, calculate SEL. */
	usb_set_lpm_sel(udev, &udev->u1_params);
	usb_set_lpm_sel(udev, &udev->u2_params);
}

/* USB 2.0 spec Section 11.24.4.5 */
static int get_hub_descriptor(struct usb_device *hdev, void *data)
{
	int i, ret, size;
	unsigned dtype;

	if (hub_is_superspeed(hdev)) {
		dtype = USB_DT_SS_HUB;
		size = USB_DT_SS_HUB_SIZE;
	} else {
		dtype = USB_DT_HUB;
		size = sizeof(struct usb_hub_descriptor);
	}

	for (i = 0; i < 3; i++) {
		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
			dtype << 8, 0, data, size,
			USB_CTRL_GET_TIMEOUT);
		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
			return ret;
	}
	return -EINVAL;
}

/*
 * USB 2.0 spec Section 11.24.2.1
 */
static int clear_hub_feature(struct usb_device *hdev, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.2
 */
int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.13
 */
static int set_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
 * for info about using port indicators
 */
static void set_port_led(
	struct usb_hub *hub,
	int port1,
	int selector
)
{
	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
			USB_PORT_FEAT_INDICATOR);
	if (status < 0)
		dev_dbg (hub->intfdev,
			"port %d indicator %s status %d\n",
			port1,
			({ char *s; switch (selector) {
			case HUB_LED_AMBER: s = "amber"; break;
			case HUB_LED_GREEN: s = "green"; break;
			case HUB_LED_OFF: s = "off"; break;
			case HUB_LED_AUTO: s = "auto"; break;
			default: s = "??"; break;
			}; s; }),
			status);
}

#define	LED_CYCLE_PERIOD	((2*HZ)/3)

static void led_work (struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, leds.work);
	struct usb_device	*hdev = hub->hdev;
	unsigned		i;
	unsigned		changed = 0;
	int			cursor = -1;

	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
		return;

	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
		unsigned	selector, mode;

		/* 30%-50% duty cycle */

		switch (hub->indicator[i]) {
		/* cycle marker */
		case INDICATOR_CYCLE:
			cursor = i;
			selector = HUB_LED_AUTO;
			mode = INDICATOR_AUTO;
			break;
		/* blinking green = sw attention */
		case INDICATOR_GREEN_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_GREEN_BLINK_OFF;
			break;
		case INDICATOR_GREEN_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_GREEN_BLINK;
			break;
		/* blinking amber = hw attention */
		case INDICATOR_AMBER_BLINK:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_AMBER_BLINK_OFF;
			break;
		case INDICATOR_AMBER_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_AMBER_BLINK;
			break;
		/* blink green/amber = reserved */
		case INDICATOR_ALT_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_ALT_BLINK_OFF;
			break;
		case INDICATOR_ALT_BLINK_OFF:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_ALT_BLINK;
			break;
		default:
			continue;
		}
		if (selector != HUB_LED_AUTO)
			changed = 1;
		set_port_led(hub, i + 1, selector);
		hub->indicator[i] = mode;
	}
	if (!changed && blinkenlights) {
		cursor++;
		cursor %= hub->descriptor->bNbrPorts;
		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
		hub->indicator[cursor] = INDICATOR_CYCLE;
		changed++;
	}
	if (changed)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
}

/* use a short timeout for hub/port status fetches */
#define	USB_STS_TIMEOUT		1000
#define	USB_STS_RETRIES		5

/*
 * USB 2.0 spec Section 11.24.2.6
 */
static int get_hub_status(struct usb_device *hdev,
		struct usb_hub_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES &&
			(status == -ETIMEDOUT || status == -EPIPE); i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

/*
 * USB 2.0 spec Section 11.24.2.7
 */
static int get_port_status(struct usb_device *hdev, int port1,
		struct usb_port_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES &&
			(status == -ETIMEDOUT || status == -EPIPE); i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

static int hub_port_status(struct usb_hub *hub, int port1,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_port_status(hub->hdev, port1, &hub->status->port);
	if (ret < 4) {
		if (ret != -ENODEV)
			dev_err(hub->intfdev,
				"%s failed (err = %d)\n", __func__, ret);
		if (ret >= 0)
			ret = -EIO;
	} else {
		*status = le16_to_cpu(hub->status->port.wPortStatus);
		*change = le16_to_cpu(hub->status->port.wPortChange);

		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static void kick_khubd(struct usb_hub *hub)
{
	unsigned long	flags;

	spin_lock_irqsave(&hub_event_lock, flags);
	if (!hub->disconnected && list_empty(&hub->event_list)) {
		list_add_tail(&hub->event_list, &hub_event_list);

		/* Suppress autosuspend until khubd runs */
		usb_autopm_get_interface_no_resume(
				to_usb_interface(hub->intfdev));
		wake_up(&khubd_wait);
	}
	spin_unlock_irqrestore(&hub_event_lock, flags);
}

void usb_kick_khubd(struct usb_device *hdev)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (hub)
		kick_khubd(hub);
}

/*
 * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
 * Notification, which indicates it had initiated remote wakeup.
 *
 * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
 * device initiates resume, so the USB core will not receive notice of the
 * resume through the normal hub interrupt URB.
 */
void usb_wakeup_notification(struct usb_device *hdev,
		unsigned int portnum)
{
	struct usb_hub *hub;

	if (!hdev)
		return;

	hub = usb_hub_to_struct_hub(hdev);
	if (hub) {
		set_bit(portnum, hub->wakeup_bits);
		kick_khubd(hub);
	}
}
EXPORT_SYMBOL_GPL(usb_wakeup_notification);

/* completion function, fires on port status changes and various faults */
static void hub_irq(struct urb *urb)
{
	struct usb_hub *hub = urb->context;
	int status = urb->status;
	unsigned i;
	unsigned long bits;

	switch (status) {
	case -ENOENT:		/* synchronous unlink */
	case -ECONNRESET:	/* async unlink */
	case -ESHUTDOWN:	/* hardware going away */
		return;

	default:		/* presumably an error */
		/* Cause a hub reset after 10 consecutive errors */
		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
		if ((++hub->nerrors < 10) || hub->error)
			goto resubmit;
		hub->error = status;
		/* FALL THROUGH */

	/* let khubd handle things */
	case 0:			/* we got data:  port status changed */
		bits = 0;
		for (i = 0; i < urb->actual_length; ++i)
			bits |= ((unsigned long) ((*hub->buffer)[i]))
					<< (i*8);
		hub->event_bits[0] = bits;
		break;
	}

	hub->nerrors = 0;

	/* Something happened, let khubd figure it out */
	kick_khubd(hub);

resubmit:
	if (hub->quiescing)
		return;

	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
			&& status != -ENODEV && status != -EPERM)
		dev_err (hub->intfdev, "resubmit --> %d\n", status);
}

/* USB 2.0 spec Section 11.24.2.3 */
static inline int
hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
{
	/* Need to clear both directions for control ep */
	if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
			USB_ENDPOINT_XFER_CONTROL) {
		int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
				HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
				devinfo ^ 0x8000, tt, NULL, 0, 1000);
		if (status)
			return status;
	}
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
			       tt, NULL, 0, 1000);
}

/*
 * enumeration blocks khubd for a long time. we use keventd instead, since
 * long blocking there is the exception, not the rule.  accordingly, HCDs
 * talking to TTs must queue control transfers (not just bulk and iso), so
 * both can talk to the same hub concurrently.
 */
static void hub_tt_work(struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, tt.clear_work);
	unsigned long		flags;

	spin_lock_irqsave (&hub->tt.lock, flags);
	while (!list_empty(&hub->tt.clear_list)) {
		struct list_head	*next;
		struct usb_tt_clear	*clear;
		struct usb_device	*hdev = hub->hdev;
		const struct hc_driver	*drv;
		int			status;

		next = hub->tt.clear_list.next;
		clear = list_entry (next, struct usb_tt_clear, clear_list);
		list_del (&clear->clear_list);

		/* drop lock so HCD can concurrently report other TT errors */
		spin_unlock_irqrestore (&hub->tt.lock, flags);
		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
		if (status && status != -ENODEV)
			dev_err (&hdev->dev,
				"clear tt %d (%04x) error %d\n",
				clear->tt, clear->devinfo, status);

		/* Tell the HCD, even if the operation failed */
		drv = clear->hcd->driver;
		if (drv->clear_tt_buffer_complete)
			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);

		kfree(clear);
		spin_lock_irqsave(&hub->tt.lock, flags);
	}
	spin_unlock_irqrestore (&hub->tt.lock, flags);
}

/**
 * usb_hub_set_port_power - control hub port's power state
 * @hdev: USB device belonging to the usb hub
 * @hub: target hub
 * @port1: port index
 * @set: expected status
 *
 * call this function to control port's power via setting or
 * clearing the port's PORT_POWER feature.
 */
int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
			   int port1, bool set)
{
	int ret;
	struct usb_port *port_dev = hub->ports[port1 - 1];

	if (set)
		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
	else
		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);

	if (!ret)
		port_dev->power_is_on = set;
	return ret;
}

/**
 * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
 * @urb: an URB associated with the failed or incomplete split transaction
 *
 * High speed HCDs use this to tell the hub driver that some split control or
 * bulk transaction failed in a way that requires clearing internal state of
 * a transaction translator.  This is normally detected (and reported) from
 * interrupt context.
 *
 * It may not be possible for that hub to handle additional full (or low)
 * speed transactions until that state is fully cleared out.
 */
int usb_hub_clear_tt_buffer(struct urb *urb)
{
	struct usb_device	*udev = urb->dev;
	int			pipe = urb->pipe;
	struct usb_tt		*tt = udev->tt;
	unsigned long		flags;
	struct usb_tt_clear	*clear;

	/* we've got to cope with an arbitrary number of pending TT clears,
	 * since each TT has "at least two" buffers that can need it (and
	 * there can be many TTs per hub).  even if they're uncommon.
	 */
	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
		/* FIXME recover somehow ... RESET_TT? */
		return -ENOMEM;
	}

	/* info that CLEAR_TT_BUFFER needs */
	clear->tt = tt->multi ? udev->ttport : 1;
	clear->devinfo = usb_pipeendpoint (pipe);
	clear->devinfo |= udev->devnum << 4;
	clear->devinfo |= usb_pipecontrol (pipe)
			? (USB_ENDPOINT_XFER_CONTROL << 11)
			: (USB_ENDPOINT_XFER_BULK << 11);
	if (usb_pipein (pipe))
		clear->devinfo |= 1 << 15;

	/* info for completion callback */
	clear->hcd = bus_to_hcd(udev->bus);
	clear->ep = urb->ep;

	/* tell keventd to clear state for this TT */
	spin_lock_irqsave (&tt->lock, flags);
	list_add_tail (&clear->clear_list, &tt->clear_list);
	schedule_work(&tt->clear_work);
	spin_unlock_irqrestore (&tt->lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);

/* If do_delay is false, return the number of milliseconds the caller
 * needs to delay.
 */
static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
{
	int port1;
	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
	unsigned delay;
	u16 wHubCharacteristics =
			le16_to_cpu(hub->descriptor->wHubCharacteristics);

	/* Enable power on each port.  Some hubs have reserved values
	 * of LPSM (> 2) in their descriptors, even though they are
	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
	 * but only emulate it.  In all cases, the ports won't work
	 * unless we send these messages to the hub.
	 */
	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
		dev_dbg(hub->intfdev, "enabling power on all ports\n");
	else
		dev_dbg(hub->intfdev, "trying to enable port power on "
				"non-switchable hub\n");
	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
		if (hub->ports[port1 - 1]->power_is_on)
			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
		else
			usb_clear_port_feature(hub->hdev, port1,
						USB_PORT_FEAT_POWER);

	/* Wait at least 100 msec for power to become stable */
	delay = max(pgood_delay, (unsigned) 100);
	if (do_delay)
		msleep(delay);
	return delay;
}

static int hub_hub_status(struct usb_hub *hub,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_hub_status(hub->hdev, &hub->status->hub);
	if (ret < 0) {
		if (ret != -ENODEV)
			dev_err(hub->intfdev,
				"%s failed (err = %d)\n", __func__, ret);
	} else {
		*status = le16_to_cpu(hub->status->hub.wHubStatus);
		*change = le16_to_cpu(hub->status->hub.wHubChange); 
		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static int hub_set_port_link_state(struct usb_hub *hub, int port1,
			unsigned int link_status)
{
	return set_port_feature(hub->hdev,
			port1 | (link_status << 3),
			USB_PORT_FEAT_LINK_STATE);
}

/*
 * If USB 3.0 ports are placed into the Disabled state, they will no longer
 * detect any device connects or disconnects.  This is generally not what the
 * USB core wants, since it expects a disabled port to produce a port status
 * change event when a new device connects.
 *
 * Instead, set the link state to Disabled, wait for the link to settle into
 * that state, clear any change bits, and then put the port into the RxDetect
 * state.
 */
static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
{
	int ret;
	int total_time;
	u16 portchange, portstatus;

	if (!hub_is_superspeed(hub->hdev))
		return -EINVAL;

	ret = hub_port_status(hub, port1, &portstatus, &portchange);
	if (ret < 0)
		return ret;

	/*
	 * USB controller Advanced Micro Devices, Inc. [AMD] FCH USB XHCI
	 * Controller [1022:7814] will have spurious result making the following
	 * usb 3.0 device hotplugging route to the 2.0 root hub and recognized
	 * as high-speed device if we set the usb 3.0 port link state to
	 * Disabled. Since it's already in USB_SS_PORT_LS_RX_DETECT state, we
	 * check the state here to avoid the bug.
	 */
	if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
				USB_SS_PORT_LS_RX_DETECT) {
		dev_dbg(&hub->ports[port1 - 1]->dev,
			 "Not disabling port; link state is RxDetect\n");
		return ret;
	}

	ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
	if (ret)
		return ret;

	/* Wait for the link to enter the disabled state. */
	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
		ret = hub_port_status(hub, port1, &portstatus, &portchange);
		if (ret < 0)
			return ret;

		if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
				USB_SS_PORT_LS_SS_DISABLED)
			break;
		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
			break;
		msleep(HUB_DEBOUNCE_STEP);
	}
	if (total_time >= HUB_DEBOUNCE_TIMEOUT)
		dev_warn(hub->intfdev, "Could not disable port %d after %d ms\n",
				port1, total_time);

	return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
}

static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
{
	struct usb_device *hdev = hub->hdev;
	int ret = 0;

	if (hub->ports[port1 - 1]->child && set_state)
		usb_set_device_state(hub->ports[port1 - 1]->child,
				USB_STATE_NOTATTACHED);
	if (!hub->error) {
		if (hub_is_superspeed(hub->hdev))
			ret = hub_usb3_port_disable(hub, port1);
		else
			ret = usb_clear_port_feature(hdev, port1,
					USB_PORT_FEAT_ENABLE);
	}
	if (ret && ret != -ENODEV)
		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
				port1, ret);
	return ret;
}

/*
 * Disable a port and mark a logical connect-change event, so that some
 * time later khubd will disconnect() any existing usb_device on the port
 * and will re-enumerate if there actually is a device attached.
 */
static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
{
	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
	hub_port_disable(hub, port1, 1);

	/* FIXME let caller ask to power down the port:
	 *  - some devices won't enumerate without a VBUS power cycle
	 *  - SRP saves power that way
	 *  - ... new call, TBD ...
	 * That's easy if this hub can switch power per-port, and
	 * khubd reactivates the port later (timer, SRP, etc).
	 * Powerdown must be optional, because of reset/DFU.
	 */

	set_bit(port1, hub->change_bits);
 	kick_khubd(hub);
}

/**
 * usb_remove_device - disable a device's port on its parent hub
 * @udev: device to be disabled and removed
 * Context: @udev locked, must be able to sleep.
 *
 * After @udev's port has been disabled, khubd is notified and it will
 * see that the device has been disconnected.  When the device is
 * physically unplugged and something is plugged in, the events will
 * be received and processed normally.
 */
int usb_remove_device(struct usb_device *udev)
{
	struct usb_hub *hub;
	struct usb_interface *intf;

	if (!udev->parent)	/* Can't remove a root hub */
		return -EINVAL;
	hub = usb_hub_to_struct_hub(udev->parent);
	intf = to_usb_interface(hub->intfdev);

	usb_autopm_get_interface(intf);
	set_bit(udev->portnum, hub->removed_bits);
	hub_port_logical_disconnect(hub, udev->portnum);
	usb_autopm_put_interface(intf);
	return 0;
}

enum hub_activation_type {
	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
};

static void hub_init_func2(struct work_struct *ws);
static void hub_init_func3(struct work_struct *ws);
static void hub_release(struct kref *kref);

static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
{
	struct usb_device *hdev = hub->hdev;
	struct usb_hcd *hcd;
	int ret;
	int port1;
	int status;
	bool need_debounce_delay = false;
	unsigned delay;

	/* Continue a partial initialization */
	if (type == HUB_INIT2 || type == HUB_INIT3) {
		device_lock(&hdev->dev);

		/* Was the hub disconnected while we were waiting? */
		if (hub->disconnected)
			goto disconnected;
		if (type == HUB_INIT2)
			goto init2;
		goto init3;
	}
	kref_get(&hub->kref);

	/* The superspeed hub except for root hub has to use Hub Depth
	 * value as an offset into the route string to locate the bits
	 * it uses to determine the downstream port number. So hub driver
	 * should send a set hub depth request to superspeed hub after
	 * the superspeed hub is set configuration in initialization or
	 * reset procedure.
	 *
	 * After a resume, port power should still be on.
	 * For any other type of activation, turn it on.
	 */
	if (type != HUB_RESUME) {
		if (hdev->parent && hub_is_superspeed(hdev)) {
			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
					HUB_SET_DEPTH, USB_RT_HUB,
					hdev->level - 1, 0, NULL, 0,
					USB_CTRL_SET_TIMEOUT);
			if (ret < 0)
				dev_err(hub->intfdev,
						"set hub depth failed\n");
		}

		/* Speed up system boot by using a delayed_work for the
		 * hub's initial power-up delays.  This is pretty awkward
		 * and the implementation looks like a home-brewed sort of
		 * setjmp/longjmp, but it saves at least 100 ms for each
		 * root hub (assuming usbcore is compiled into the kernel
		 * rather than as a module).  It adds up.
		 *
		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
		 * because for those activation types the ports have to be
		 * operational when we return.  In theory this could be done
		 * for HUB_POST_RESET, but it's easier not to.
		 */
		if (type == HUB_INIT) {
			delay = hub_power_on(hub, false);
#ifdef CONFIG_USB_OTG
			if (hdev->bus->is_b_host)
				goto init2;
#endif
			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
			schedule_delayed_work(&hub->init_work,
					msecs_to_jiffies(delay));

			/* Suppress autosuspend until init is done */
			usb_autopm_get_interface_no_resume(
					to_usb_interface(hub->intfdev));
			return;		/* Continues at init2: below */
		} else if (type == HUB_RESET_RESUME) {
			/* The internal host controller state for the hub device
			 * may be gone after a host power loss on system resume.
			 * Update the device's info so the HW knows it's a hub.
			 */
			hcd = bus_to_hcd(hdev->bus);
			if (hcd->driver->update_hub_device) {
				ret = hcd->driver->update_hub_device(hcd, hdev,
						&hub->tt, GFP_NOIO);
				if (ret < 0) {
					dev_err(hub->intfdev, "Host not "
							"accepting hub info "
							"update.\n");
					dev_err(hub->intfdev, "LS/FS devices "
							"and hubs may not work "
							"under this hub\n.");
				}
			}
			hub_power_on(hub, true);
		} else {
			hub_power_on(hub, true);
		}
	}
 init2:

	/* Check each port and set hub->change_bits to let khubd know
	 * which ports need attention.
	 */
	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
		struct usb_device *udev = hub->ports[port1 - 1]->child;
		u16 portstatus, portchange;

		portstatus = portchange = 0;
		status = hub_port_status(hub, port1, &portstatus, &portchange);
		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
			dev_dbg(hub->intfdev,
					"port %d: status %04x change %04x\n",
					port1, portstatus, portchange);

		/* After anything other than HUB_RESUME (i.e., initialization
		 * or any sort of reset), every port should be disabled.
		 * Unconnected ports should likewise be disabled (paranoia),
		 * and so should ports for which we have no usb_device.
		 */
		if ((portstatus & USB_PORT_STAT_ENABLE) && (
				type != HUB_RESUME ||
				!(portstatus & USB_PORT_STAT_CONNECTION) ||
				!udev ||
				udev->state == USB_STATE_NOTATTACHED)) {
			/*
			 * USB3 protocol ports will automatically transition
			 * to Enabled state when detect an USB3.0 device attach.
			 * Do not disable USB3 protocol ports.
			 */
			if (!hub_is_superspeed(hdev)) {
				usb_clear_port_feature(hdev, port1,
						   USB_PORT_FEAT_ENABLE);
				portstatus &= ~USB_PORT_STAT_ENABLE;
			} else {
				/* Pretend that power was lost for USB3 devs */
				portstatus &= ~USB_PORT_STAT_ENABLE;
			}
		}

		/* Clear status-change flags; we'll debounce later */
		if (portchange & USB_PORT_STAT_C_CONNECTION) {
			need_debounce_delay = true;
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		}
		if (portchange & USB_PORT_STAT_C_ENABLE) {
			need_debounce_delay = true;
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_ENABLE);
		}
		if (portchange & USB_PORT_STAT_C_RESET) {
			need_debounce_delay = true;
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_RESET);
		}
		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
				hub_is_superspeed(hub->hdev)) {
			need_debounce_delay = true;
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_BH_PORT_RESET);
		}
		/* We can forget about a "removed" device when there's a
		 * physical disconnect or the connect status changes.
		 */
		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
				(portchange & USB_PORT_STAT_C_CONNECTION))
			clear_bit(port1, hub->removed_bits);

		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
			/* Tell khubd to disconnect the device or
			 * check for a new connection
			 */
			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
			    (portstatus & USB_PORT_STAT_OVERCURRENT))
				set_bit(port1, hub->change_bits);

		} else if (portstatus & USB_PORT_STAT_ENABLE) {
			bool port_resumed = (portstatus &
					USB_PORT_STAT_LINK_STATE) ==
				USB_SS_PORT_LS_U0;
			/* The power session apparently survived the resume.
			 * If there was an overcurrent or suspend change
			 * (i.e., remote wakeup request), have khubd
			 * take care of it.  Look at the port link state
			 * for USB 3.0 hubs, since they don't have a suspend
			 * change bit, and they don't set the port link change
			 * bit on device-initiated resume.
			 */
			if (portchange || (hub_is_superspeed(hub->hdev) &&
						port_resumed))
				set_bit(port1, hub->change_bits);

		} else if (udev->persist_enabled) {
			struct usb_port *port_dev = hub->ports[port1 - 1];

#ifdef CONFIG_PM
			udev->reset_resume = 1;
#endif
			/* Don't set the change_bits when the device
			 * was powered off.
			 */
			if (port_dev->power_is_on)
				set_bit(port1, hub->change_bits);

		} else {
			/* The power session is gone; tell khubd */
			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
			set_bit(port1, hub->change_bits);
		}
	}

	/* If no port-status-change flags were set, we don't need any
	 * debouncing.  If flags were set we can try to debounce the
	 * ports all at once right now, instead of letting khubd do them
	 * one at a time later on.
	 *
	 * If any port-status changes do occur during this delay, khubd
	 * will see them later and handle them normally.
	 */
	if (need_debounce_delay) {
#ifdef CONFIG_USB_OTG
		if (hdev->bus->is_b_host && type == HUB_INIT)
			goto init3;
#endif

		delay = HUB_DEBOUNCE_STABLE;

		/* Don't do a long sleep inside a workqueue routine */
		if (type == HUB_INIT2) {
			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
			schedule_delayed_work(&hub->init_work,
					msecs_to_jiffies(delay));
			device_unlock(&hdev->dev);
			return;		/* Continues at init3: below */
		} else {
			msleep(delay);
		}
	}
 init3:
	hub->quiescing = 0;

	status = usb_submit_urb(hub->urb, GFP_NOIO);
	if (status < 0)
		dev_err(hub->intfdev, "activate --> %d\n", status);
	if (hub->has_indicators && blinkenlights)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);

	/* Scan all ports that need attention */
	kick_khubd(hub);

	if (type == HUB_INIT2 || type == HUB_INIT3) {
		/* Allow autosuspend if it was suppressed */
 disconnected:
		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
		device_unlock(&hdev->dev);
	}

	kref_put(&hub->kref, hub_release);
}

/* Implement the continuations for the delays above */
static void hub_init_func2(struct work_struct *ws)
{
	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);

	hub_activate(hub, HUB_INIT2);
}

static void hub_init_func3(struct work_struct *ws)
{
	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);

	hub_activate(hub, HUB_INIT3);
}

enum hub_quiescing_type {
	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
};

static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
{
	struct usb_device *hdev = hub->hdev;
	int i;

	/* khubd and related activity won't re-trigger */
	hub->quiescing = 1;

	if (type != HUB_SUSPEND) {
		/* Disconnect all the children */
		for (i = 0; i < hdev->maxchild; ++i) {
			if (hub->ports[i]->child)
				usb_disconnect(&hub->ports[i]->child);
		}
	}

	/* Stop khubd and related activity */
	usb_kill_urb(hub->urb);
	if (hub->has_indicators)
		cancel_delayed_work_sync(&hub->leds);
	if (hub->tt.hub)
		flush_work(&hub->tt.clear_work);
}

/* caller has locked the hub device */
static int hub_pre_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_quiesce(hub, HUB_PRE_RESET);
	return 0;
}

/* caller has locked the hub device */
static int hub_post_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_activate(hub, HUB_POST_RESET);
	return 0;
}

static int hub_configure(struct usb_hub *hub,
	struct usb_endpoint_descriptor *endpoint)
{
	struct usb_hcd *hcd;
	struct usb_device *hdev = hub->hdev;
	struct device *hub_dev = hub->intfdev;
	u16 hubstatus, hubchange;
	u16 wHubCharacteristics;
	unsigned int pipe;
	int maxp, ret, i;
	char *message = "out of memory";
	unsigned unit_load;
	unsigned full_load;

	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
	if (!hub->buffer) {
		ret = -ENOMEM;
		goto fail;
	}

	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
	if (!hub->status) {
		ret = -ENOMEM;
		goto fail;
	}
	mutex_init(&hub->status_mutex);

	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
	if (!hub->descriptor) {
		ret = -ENOMEM;
		goto fail;
	}

	/* Request the entire hub descriptor.
	 * hub->descriptor can handle USB_MAXCHILDREN ports,
	 * but the hub can/will return fewer bytes here.
	 */
	ret = get_hub_descriptor(hdev, hub->descriptor);
	if (ret < 0) {
		message = "can't read hub descriptor";
		goto fail;
	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
		message = "hub has too many ports!";
		ret = -ENODEV;
		goto fail;
	} else if (hub->descriptor->bNbrPorts == 0) {
		message = "hub doesn't have any ports!";
		ret = -ENODEV;
		goto fail;
	}

	hdev->maxchild = hub->descriptor->bNbrPorts;
	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
		(hdev->maxchild == 1) ? "" : "s");

	hub->ports = kzalloc(hdev->maxchild * sizeof(struct usb_port *),
			     GFP_KERNEL);
	if (!hub->ports) {
		ret = -ENOMEM;
		goto fail;
	}

	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
	if (hub_is_superspeed(hdev)) {
		unit_load = 150;
		full_load = 900;
	} else {
		unit_load = 100;
		full_load = 500;
	}

	/* FIXME for USB 3.0, skip for now */
	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
			!(hub_is_superspeed(hdev))) {
		int	i;
		char	portstr [USB_MAXCHILDREN + 1];

		for (i = 0; i < hdev->maxchild; i++)
			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
				? 'F' : 'R';
		portstr[hdev->maxchild] = 0;
		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
	} else
		dev_dbg(hub_dev, "standalone hub\n");

	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
	case HUB_CHAR_COMMON_LPSM:
		dev_dbg(hub_dev, "ganged power switching\n");
		break;
	case HUB_CHAR_INDV_PORT_LPSM:
		dev_dbg(hub_dev, "individual port power switching\n");
		break;
	case HUB_CHAR_NO_LPSM:
	case HUB_CHAR_LPSM:
		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
		break;
	}

	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
	case HUB_CHAR_COMMON_OCPM:
		dev_dbg(hub_dev, "global over-current protection\n");
		break;
	case HUB_CHAR_INDV_PORT_OCPM:
		dev_dbg(hub_dev, "individual port over-current protection\n");
		break;
	case HUB_CHAR_NO_OCPM:
	case HUB_CHAR_OCPM:
		dev_dbg(hub_dev, "no over-current protection\n");
		break;
	}

	spin_lock_init (&hub->tt.lock);
	INIT_LIST_HEAD (&hub->tt.clear_list);
	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
	switch (hdev->descriptor.bDeviceProtocol) {
	case USB_HUB_PR_FS:
		break;
	case USB_HUB_PR_HS_SINGLE_TT:
		dev_dbg(hub_dev, "Single TT\n");
		hub->tt.hub = hdev;
		break;
	case USB_HUB_PR_HS_MULTI_TT:
		ret = usb_set_interface(hdev, 0, 1);
		if (ret == 0) {
			dev_dbg(hub_dev, "TT per port\n");
			hub->tt.multi = 1;
		} else
			dev_err(hub_dev, "Using single TT (err %d)\n",
				ret);
		hub->tt.hub = hdev;
		break;
	case USB_HUB_PR_SS:
		/* USB 3.0 hubs don't have a TT */
		break;
	default:
		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
			hdev->descriptor.bDeviceProtocol);
		break;
	}

	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
		case HUB_TTTT_8_BITS:
			if (hdev->descriptor.bDeviceProtocol != 0) {
				hub->tt.think_time = 666;
				dev_dbg(hub_dev, "TT requires at most %d "
						"FS bit times (%d ns)\n",
					8, hub->tt.think_time);
			}
			break;
		case HUB_TTTT_16_BITS:
			hub->tt.think_time = 666 * 2;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				16, hub->tt.think_time);
			break;
		case HUB_TTTT_24_BITS:
			hub->tt.think_time = 666 * 3;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				24, hub->tt.think_time);
			break;
		case HUB_TTTT_32_BITS:
			hub->tt.think_time = 666 * 4;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				32, hub->tt.think_time);
			break;
	}

	/* probe() zeroes hub->indicator[] */
	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
		hub->has_indicators = 1;
		dev_dbg(hub_dev, "Port indicators are supported\n");
	}

	dev_dbg(hub_dev, "power on to power good time: %dms\n",
		hub->descriptor->bPwrOn2PwrGood * 2);

	/* power budgeting mostly matters with bus-powered hubs,
	 * and battery-powered root hubs (may provide just 8 mA).
	 */
	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
	if (ret < 2) {
		message = "can't get hub status";
		goto fail;
	}
	le16_to_cpus(&hubstatus);
	hcd = bus_to_hcd(hdev->bus);
	if (hdev == hdev->bus->root_hub) {
		if (hcd->power_budget > 0)
			hdev->bus_mA = hcd->power_budget;
		else
			hdev->bus_mA = full_load * hdev->maxchild;
		if (hdev->bus_mA >= full_load)
			hub->mA_per_port = full_load;
		else {
			hub->mA_per_port = hdev->bus_mA;
			hub->limited_power = 1;
		}
	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
		int remaining = hdev->bus_mA -
			hub->descriptor->bHubContrCurrent;

		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
			hub->descriptor->bHubContrCurrent);
		hub->limited_power = 1;

		if (remaining < hdev->maxchild * unit_load)
			dev_warn(hub_dev,
					"insufficient power available "
					"to use all downstream ports\n");
		hub->mA_per_port = unit_load;	/* 7.2.1 */

	} else {	/* Self-powered external hub */
		/* FIXME: What about battery-powered external hubs that
		 * provide less current per port? */
		hub->mA_per_port = full_load;
	}
	if (hub->mA_per_port < full_load)
		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
				hub->mA_per_port);

	/* Update the HCD's internal representation of this hub before khubd
	 * starts getting port status changes for devices under the hub.
	 */
	if (hcd->driver->update_hub_device) {
		ret = hcd->driver->update_hub_device(hcd, hdev,
				&hub->tt, GFP_KERNEL);
		if (ret < 0) {
			message = "can't update HCD hub info";
			goto fail;
		}
	}

	ret = hub_hub_status(hub, &hubstatus, &hubchange);
	if (ret < 0) {
		message = "can't get hub status";
		goto fail;
	}

	/* local power status reports aren't always correct */
	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
		dev_dbg(hub_dev, "local power source is %s\n",
			(hubstatus & HUB_STATUS_LOCAL_POWER)
			? "lost (inactive)" : "good");

	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
		dev_dbg(hub_dev, "%sover-current condition exists\n",
			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");

	/* set up the interrupt endpoint
	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
	 * bytes as USB2.0[11.12.3] says because some hubs are known
	 * to send more data (and thus cause overflow). For root hubs,
	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
	 * to be big enough for at least USB_MAXCHILDREN ports. */
	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));

	if (maxp > sizeof(*hub->buffer))
		maxp = sizeof(*hub->buffer);

	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!hub->urb) {
		ret = -ENOMEM;
		goto fail;
	}

	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
		hub, endpoint->bInterval);

	/* maybe cycle the hub leds */
	if (hub->has_indicators && blinkenlights)
		hub->indicator [0] = INDICATOR_CYCLE;

	for (i = 0; i < hdev->maxchild; i++) {
		ret = usb_hub_create_port_device(hub, i + 1);
		if (ret < 0) {
			dev_err(hub->intfdev,
				"couldn't create port%d device.\n", i + 1);
			hdev->maxchild = i;
			goto fail_keep_maxchild;
		}
	}

	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);

	hub_activate(hub, HUB_INIT);
	return 0;

fail:
	hdev->maxchild = 0;
fail_keep_maxchild:
	dev_err (hub_dev, "config failed, %s (err %d)\n",
			message, ret);
	/* hub_disconnect() frees urb and descriptor */
	return ret;
}

static void hub_release(struct kref *kref)
{
	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);

	usb_put_intf(to_usb_interface(hub->intfdev));
	kfree(hub);
}

static unsigned highspeed_hubs;

static void hub_disconnect(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);
	struct usb_device *hdev = interface_to_usbdev(intf);
	int port1;

	/* Take the hub off the event list and don't let it be added again */
	spin_lock_irq(&hub_event_lock);
	if (!list_empty(&hub->event_list)) {
		list_del_init(&hub->event_list);
		usb_autopm_put_interface_no_suspend(intf);
	}
	hub->disconnected = 1;
	spin_unlock_irq(&hub_event_lock);

	/* Disconnect all children and quiesce the hub */
	hub->error = 0;
	hub_quiesce(hub, HUB_DISCONNECT);

	/* Avoid races with recursively_mark_NOTATTACHED() */
	spin_lock_irq(&device_state_lock);
	port1 = hdev->maxchild;
	hdev->maxchild = 0;
	usb_set_intfdata(intf, NULL);
	spin_unlock_irq(&device_state_lock);

	for (; port1 > 0; --port1)
		usb_hub_remove_port_device(hub, port1);

	if (hub->hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs--;

	usb_free_urb(hub->urb);
	kfree(hub->ports);
	kfree(hub->descriptor);
	kfree(hub->status);
	kfree(hub->buffer);

	pm_suspend_ignore_children(&intf->dev, false);
	kref_put(&hub->kref, hub_release);
}

static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_host_interface *desc;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_device *hdev;
	struct usb_hub *hub;

	desc = intf->cur_altsetting;
	hdev = interface_to_usbdev(intf);

	/*
	 * Set default autosuspend delay as 0 to speedup bus suspend,
	 * based on the below considerations:
	 *
	 * - Unlike other drivers, the hub driver does not rely on the
	 *   autosuspend delay to provide enough time to handle a wakeup
	 *   event, and the submitted status URB is just to check future
	 *   change on hub downstream ports, so it is safe to do it.
	 *
	 * - The patch might cause one or more auto supend/resume for
	 *   below very rare devices when they are plugged into hub
	 *   first time:
	 *
	 *   	devices having trouble initializing, and disconnect
	 *   	themselves from the bus and then reconnect a second
	 *   	or so later
	 *
	 *   	devices just for downloading firmware, and disconnects
	 *   	themselves after completing it
	 *
	 *   For these quite rare devices, their drivers may change the
	 *   autosuspend delay of their parent hub in the probe() to one
	 *   appropriate value to avoid the subtle problem if someone
	 *   does care it.
	 *
	 * - The patch may cause one or more auto suspend/resume on
	 *   hub during running 'lsusb', but it is probably too
	 *   infrequent to worry about.
	 *
	 * - Change autosuspend delay of hub can avoid unnecessary auto
	 *   suspend timer for hub, also may decrease power consumption
	 *   of USB bus.
	 *
	 * - If user has indicated to prevent autosuspend by passing
	 *   usbcore.autosuspend = -1 then keep autosuspend disabled.
	 */
#ifdef CONFIG_PM_RUNTIME
	if (hdev->dev.power.autosuspend_delay >= 0)
		pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
#endif

	/*
	 * Hubs have proper suspend/resume support, except for root hubs
	 * where the controller driver doesn't have bus_suspend and
	 * bus_resume methods.
	 */
	if (hdev->parent) {		/* normal device */
		usb_enable_autosuspend(hdev);
	} else {			/* root hub */
		const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;

		if (drv->bus_suspend && drv->bus_resume)
			usb_enable_autosuspend(hdev);
	}

	if (hdev->level == MAX_TOPO_LEVEL) {
		dev_err(&intf->dev,
			"Unsupported bus topology: hub nested too deep\n");
		return -E2BIG;
	}

#ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
	if (hdev->parent) {
		dev_warn(&intf->dev, "ignoring external hub\n");
		otg_send_event(OTG_EVENT_HUB_NOT_SUPPORTED);
		return -ENODEV;
	}
#endif

	/* Some hubs have a subclass of 1, which AFAICT according to the */
	/*  specs is not defined, but it works */
	if ((desc->desc.bInterfaceSubClass != 0) &&
	    (desc->desc.bInterfaceSubClass != 1)) {
descriptor_error:
		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
		return -EIO;
	}

	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
	if (desc->desc.bNumEndpoints != 1)
		goto descriptor_error;

	endpoint = &desc->endpoint[0].desc;

	/* If it's not an interrupt in endpoint, we'd better punt! */
	if (!usb_endpoint_is_int_in(endpoint))
		goto descriptor_error;

	/* We found a hub */
	dev_info (&intf->dev, "USB hub found\n");

	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
	if (!hub) {
		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
		return -ENOMEM;
	}

	kref_init(&hub->kref);
	INIT_LIST_HEAD(&hub->event_list);
	hub->intfdev = &intf->dev;
	hub->hdev = hdev;
	INIT_DELAYED_WORK(&hub->leds, led_work);
	INIT_DELAYED_WORK(&hub->init_work, NULL);
	usb_get_intf(intf);

	usb_set_intfdata (intf, hub);
	intf->needs_remote_wakeup = 1;
	pm_suspend_ignore_children(&intf->dev, true);

	if (hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs++;

	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
		hub->quirk_check_port_auto_suspend = 1;

	if (hub_configure(hub, endpoint) >= 0)
		return 0;

	hub_disconnect (intf);
	return -ENODEV;
}

static int
hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
{
	struct usb_device *hdev = interface_to_usbdev (intf);
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (!hub)
		return -ENODEV;

	/* assert ifno == 0 (part of hub spec) */
	switch (code) {
	case USBDEVFS_HUB_PORTINFO: {
		struct usbdevfs_hub_portinfo *info = user_data;
		int i;

		spin_lock_irq(&device_state_lock);
		if (hdev->devnum <= 0)
			info->nports = 0;
		else {
			info->nports = hdev->maxchild;
			for (i = 0; i < info->nports; i++) {
				if (hub->ports[i]->child == NULL)
					info->port[i] = 0;
				else
					info->port[i] =
						hub->ports[i]->child->devnum;
			}
		}
		spin_unlock_irq(&device_state_lock);

		return info->nports + 1;
		}

	default:
		return -ENOSYS;
	}
}

/*
 * Allow user programs to claim ports on a hub.  When a device is attached
 * to one of these "claimed" ports, the program will "own" the device.
 */
static int find_port_owner(struct usb_device *hdev, unsigned port1,
		struct dev_state ***ppowner)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (!hub || (hdev->state == USB_STATE_NOTATTACHED))
		return -ENODEV;
	if (port1 == 0 || port1 > hdev->maxchild)
		return -EINVAL;

	/* Devices not managed by the hub driver
	 * will always have maxchild equal to 0.
	 */
	*ppowner = &(hub->ports[port1 - 1]->port_owner);
	return 0;
}

/* In the following three functions, the caller must hold hdev's lock */
int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
		       struct dev_state *owner)
{
	int rc;
	struct dev_state **powner;

	rc = find_port_owner(hdev, port1, &powner);
	if (rc)
		return rc;
	if (*powner)
		return -EBUSY;
	*powner = owner;
	return rc;
}

int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
			 struct dev_state *owner)
{
	int rc;
	struct dev_state **powner;

	rc = find_port_owner(hdev, port1, &powner);
	if (rc)
		return rc;
	if (*powner != owner)
		return -ENOENT;
	*powner = NULL;
	return rc;
}

void usb_hub_release_all_ports(struct usb_device *hdev, struct dev_state *owner)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
	int n;

	for (n = 0; n < hdev->maxchild; n++) {
		if (hub->ports[n]->port_owner == owner)
			hub->ports[n]->port_owner = NULL;
	}

}

/* The caller must hold udev's lock */
bool usb_device_is_owned(struct usb_device *udev)
{
	struct usb_hub *hub;

	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
		return false;

	hub = usb_hub_to_struct_hub(udev->parent);
	if (!hub)
		return false;

	return !!hub->ports[udev->portnum - 1]->port_owner;
}

static void recursively_mark_NOTATTACHED(struct usb_device *udev)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
	int i;

	for (i = 0; i < udev->maxchild; ++i) {
		if (hub->ports[i]->child)
			recursively_mark_NOTATTACHED(hub->ports[i]->child);
	}
	if (udev->state == USB_STATE_SUSPENDED)
		udev->active_duration -= jiffies;
	udev->state = USB_STATE_NOTATTACHED;
}

/**
 * usb_set_device_state - change a device's current state (usbcore, hcds)
 * @udev: pointer to device whose state should be changed
 * @new_state: new state value to be stored
 *
 * udev->state is _not_ fully protected by the device lock.  Although
 * most transitions are made only while holding the lock, the state can
 * can change to USB_STATE_NOTATTACHED at almost any time.  This
 * is so that devices can be marked as disconnected as soon as possible,
 * without having to wait for any semaphores to be released.  As a result,
 * all changes to any device's state must be protected by the
 * device_state_lock spinlock.
 *
 * Once a device has been added to the device tree, all changes to its state
 * should be made using this routine.  The state should _not_ be set directly.
 *
 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
 * Otherwise udev->state is set to new_state, and if new_state is
 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
 * to USB_STATE_NOTATTACHED.
 */
void usb_set_device_state(struct usb_device *udev,
		enum usb_device_state new_state)
{
	unsigned long flags;
	int wakeup = -1;

	spin_lock_irqsave(&device_state_lock, flags);
	if (udev->state == USB_STATE_NOTATTACHED)
		;	/* do nothing */
	else if (new_state != USB_STATE_NOTATTACHED) {

		/* root hub wakeup capabilities are managed out-of-band
		 * and may involve silicon errata ... ignore them here.
		 */
		if (udev->parent) {
			if (udev->state == USB_STATE_SUSPENDED
					|| new_state == USB_STATE_SUSPENDED)
				;	/* No change to wakeup settings */
			else if (new_state == USB_STATE_CONFIGURED)
				wakeup = (udev->quirks &
					USB_QUIRK_IGNORE_REMOTE_WAKEUP) ? 0 :
					udev->actconfig->desc.bmAttributes &
					USB_CONFIG_ATT_WAKEUP;
			else
				wakeup = 0;
		}
		if (udev->state == USB_STATE_SUSPENDED &&
			new_state != USB_STATE_SUSPENDED)
			udev->active_duration -= jiffies;
		else if (new_state == USB_STATE_SUSPENDED &&
				udev->state != USB_STATE_SUSPENDED)
			udev->active_duration += jiffies;
		udev->state = new_state;
	} else
		recursively_mark_NOTATTACHED(udev);
	spin_unlock_irqrestore(&device_state_lock, flags);
	if (wakeup >= 0)
		device_set_wakeup_capable(&udev->dev, wakeup);
}
EXPORT_SYMBOL_GPL(usb_set_device_state);

/*
 * Choose a device number.
 *
 * Device numbers are used as filenames in usbfs.  On USB-1.1 and
 * USB-2.0 buses they are also used as device addresses, however on
 * USB-3.0 buses the address is assigned by the controller hardware
 * and it usually is not the same as the device number.
 *
 * WUSB devices are simple: they have no hubs behind, so the mapping
 * device <-> virtual port number becomes 1:1. Why? to simplify the
 * life of the device connection logic in
 * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
 * handshake we need to assign a temporary address in the unauthorized
 * space. For simplicity we use the first virtual port number found to
 * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
 * and that becomes it's address [X < 128] or its unauthorized address
 * [X | 0x80].
 *
 * We add 1 as an offset to the one-based USB-stack port number
 * (zero-based wusb virtual port index) for two reasons: (a) dev addr
 * 0 is reserved by USB for default address; (b) Linux's USB stack
 * uses always #1 for the root hub of the controller. So USB stack's
 * port #1, which is wusb virtual-port #0 has address #2.
 *
 * Devices connected under xHCI are not as simple.  The host controller
 * supports virtualization, so the hardware assigns device addresses and
 * the HCD must setup data structures before issuing a set address
 * command to the hardware.
 */
static void choose_devnum(struct usb_device *udev)
{
	int		devnum;
	struct usb_bus	*bus = udev->bus;

	/* If khubd ever becomes multithreaded, this will need a lock */
	if (udev->wusb) {
		devnum = udev->portnum + 1;
		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
	} else {
		/* Try to allocate the next devnum beginning at
		 * bus->devnum_next. */
		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
					    bus->devnum_next);
		if (devnum >= 128)
			devnum = find_next_zero_bit(bus->devmap.devicemap,
						    128, 1);
		bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
	}
	if (devnum < 128) {
		set_bit(devnum, bus->devmap.devicemap);
		udev->devnum = devnum;
	}
}

static void release_devnum(struct usb_device *udev)
{
	if (udev->devnum > 0) {
		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
		udev->devnum = -1;
	}
}

static void update_devnum(struct usb_device *udev, int devnum)
{
	/* The address for a WUSB device is managed by wusbcore. */
	if (!udev->wusb)
		udev->devnum = devnum;
}

static void hub_free_dev(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	/* Root hubs aren't real devices, so don't free HCD resources */
	if (hcd->driver->free_dev && udev->parent)
		hcd->driver->free_dev(hcd, udev);
}

/**
 * usb_disconnect - disconnect a device (usbcore-internal)
 * @pdev: pointer to device being disconnected
 * Context: !in_interrupt ()
 *
 * Something got disconnected. Get rid of it and all of its children.
 *
 * If *pdev is a normal device then the parent hub must already be locked.
 * If *pdev is a root hub then this routine will acquire the
 * usb_bus_list_lock on behalf of the caller.
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 */
void usb_disconnect(struct usb_device **pdev)
{
	struct usb_device	*udev = *pdev;
	struct usb_hub		*hub = usb_hub_to_struct_hub(udev);
	int			i;

	/* mark the device as inactive, so any further urb submissions for
	 * this device (and any of its children) will fail immediately.
	 * this quiesces everything except pending urbs.
	 */
	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
	dev_info(&udev->dev, "USB disconnect, device number %d\n",
			udev->devnum);

#ifdef CONFIG_USB_OTG
	if (udev->bus->hnp_support && udev->portnum == udev->bus->otg_port) {
		cancel_delayed_work_sync(&udev->bus->hnp_polling);
		udev->bus->hnp_support = 0;
	}
#endif

	usb_lock_device(udev);

	/* Free up all the children before we remove this device */
	for (i = 0; i < udev->maxchild; i++) {
		if (hub && hub->ports[i]->child)
			usb_disconnect(&hub->ports[i]->child);
	}

	/* deallocate hcd/hardware state ... nuking all pending urbs and
	 * cleaning up all state associated with the current configuration
	 * so that the hardware is now fully quiesced.
	 */
	dev_dbg (&udev->dev, "unregistering device\n");
	usb_disable_device(udev, 0);
	usb_hcd_synchronize_unlinks(udev);

	if (udev->parent) {
		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
		struct usb_port	*port_dev = NULL;

		if (hub)
			port_dev = hub->ports[udev->portnum - 1];

		sysfs_remove_link(&udev->dev.kobj, "port");

		if (port_dev) {
			sysfs_remove_link(&port_dev->dev.kobj, "device");
			if (!port_dev->did_runtime_put)
				pm_runtime_put(&port_dev->dev);
			else
				port_dev->did_runtime_put = false;
		}
	}

	usb_remove_ep_devs(&udev->ep0);
	usb_unlock_device(udev);

	/* Unregister the device.  The device driver is responsible
	 * for de-configuring the device and invoking the remove-device
	 * notifier chain (used by usbfs and possibly others).
	 */
	device_del(&udev->dev);

	/* Free the device number and delete the parent's children[]
	 * (or root_hub) pointer.
	 */
	release_devnum(udev);

	/* Avoid races with recursively_mark_NOTATTACHED() */
	spin_lock_irq(&device_state_lock);
	*pdev = NULL;
	spin_unlock_irq(&device_state_lock);

	hub_free_dev(udev);

	put_device(&udev->dev);
}

#ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
static void show_string(struct usb_device *udev, char *id, char *string)
{
	if (!string)
		return;
	dev_info(&udev->dev, "%s: %s\n", id, string);
}

static void announce_device(struct usb_device *udev)
{
	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
		le16_to_cpu(udev->descriptor.idVendor),
		le16_to_cpu(udev->descriptor.idProduct));
	dev_info(&udev->dev,
		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
		udev->descriptor.iManufacturer,
		udev->descriptor.iProduct,
		udev->descriptor.iSerialNumber);
	show_string(udev, "Product", udev->product);
	show_string(udev, "Manufacturer", udev->manufacturer);
	show_string(udev, "SerialNumber", udev->serial);
}
#else
static inline void announce_device(struct usb_device *udev) { }
#endif

#ifdef	CONFIG_USB_OTG
#include "otg_whitelist.h"
#endif

/**
 * usb_enumerate_device_otg - FIXME (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * Finish enumeration for On-The-Go devices
 */
static int usb_enumerate_device_otg(struct usb_device *udev)
{
	int err = 0;

#ifdef	CONFIG_USB_OTG
	bool old_otg = false;
	/*
	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
	 * to wake us after we've powered off VBUS; and HNP, switching roles
	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
	 */
	if (!udev->bus->is_b_host
			&& udev->config
			&& udev->parent == udev->bus->root_hub) {
		struct usb_otg_descriptor	*desc = NULL;
		struct usb_bus			*bus = udev->bus;

		/* descriptor may appear anywhere in config */
		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
					le16_to_cpu(udev->config[0].desc.wTotalLength),
					USB_DT_OTG, (void **) &desc) == 0) {
			if (desc->bmAttributes & USB_OTG_HNP) {
				unsigned		port1 = udev->portnum;

				dev_info(&udev->dev,
					"Dual-Role OTG device on %sHNP port\n",
					(port1 == bus->otg_port)
						? "" : "non-");

				/* a_alt_hnp_support is obsoleted */
				if (port1 != bus->otg_port)
					goto out;

				bus->hnp_support = 1;

				/* a_hnp_support is not required for devices
				 * compliant to revision 2.0 or subsequent
				 * versions.
				 */

				if ((le16_to_cpu(desc->bLength) ==
						USB_DT_OTG_SIZE) &&
					le16_to_cpu(desc->bcdOTG) >= 0x0200)
					goto out;

				/* Legacy B-device i.e compliant to spec
				 * revision 1.3 expect A-device to set
				 * a_hnp_support or b_hnp_enable before
				 * selecting configuration.
				 */
				old_otg = true;

				/* enable HNP before suspend, it's simpler */
				err = usb_control_msg(udev,
					usb_sndctrlpipe(udev, 0),
					USB_REQ_SET_FEATURE, 0,
					USB_DEVICE_A_HNP_SUPPORT,
					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
				if (err < 0) {
					/* OTG MESSAGE: report errors here,
					 * customize to match your product.
					 */
					dev_info(&udev->dev,
						"can't set HNP mode: %d\n",
						err);
					bus->hnp_support = 0;
				}
			}
		}
	}
out:
	if ((udev->quirks & USB_QUIRK_OTG_PET)) {
		if (le16_to_cpu(udev->descriptor.bcdDevice) &
			OTG_TTST_VBUS_OFF)
			udev->bus->otg_vbus_off = 1;
		if (udev->bus->is_b_host || old_otg)
			udev->bus->quick_hnp = 1;
	}

	if (!is_targeted(udev)) {

		otg_send_event(OTG_EVENT_DEV_NOT_SUPPORTED);

		/* Maybe it can talk to us, though we can't talk to it.
		 * (Includes HNP test device.)
		 */
		if (udev->bus->hnp_support) {
			err = usb_port_suspend(udev, PMSG_SUSPEND);
			if (err < 0)
				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
		}
		err = -ENOTSUPP;
	} else if (udev->bus->hnp_support &&
		udev->portnum == udev->bus->otg_port) {
		/* HNP polling is introduced in OTG supplement Rev 2.0
		 * and older devices may not support. Work is not
		 * re-armed if device returns STALL. B-Host also perform
		 * HNP polling.
		 */
		if (udev->bus->quick_hnp)
			schedule_delayed_work(&udev->bus->hnp_polling,
				msecs_to_jiffies(OTG_TTST_SUSP));
		else
			schedule_delayed_work(&udev->bus->hnp_polling,
				msecs_to_jiffies(THOST_REQ_POLL));
	}
#endif
	return err;
}


/**
 * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * This is only called by usb_new_device() and usb_authorize_device()
 * and FIXME -- all comments that apply to them apply here wrt to
 * environment.
 *
 * If the device is WUSB and not authorized, we don't attempt to read
 * the string descriptors, as they will be errored out by the device
 * until it has been authorized.
 */
static int usb_enumerate_device(struct usb_device *udev)
{
	int err;

	if (udev->config == NULL) {
		err = usb_get_configuration(udev);
		if (err < 0) {
			if (err != -ENODEV)
				dev_err(&udev->dev, "can't read configurations, error %d\n",
						err);
			return err;
		}
	}

	/* read the standard strings and cache them if present */
	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
	udev->manufacturer = usb_cache_string(udev,
					      udev->descriptor.iManufacturer);
	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);

	err = usb_enumerate_device_otg(udev);
	if (err < 0)
		return err;

	usb_detect_interface_quirks(udev);

	return 0;
}

static void set_usb_port_removable(struct usb_device *udev)
{
	struct usb_device *hdev = udev->parent;
	struct usb_hub *hub;
	u8 port = udev->portnum;
	u16 wHubCharacteristics;
	bool removable = true;

	if (!hdev)
		return;

	hub = usb_hub_to_struct_hub(udev->parent);
	if (!hub)
		return;

	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);

	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
		return;

	if (hub_is_superspeed(hdev)) {
		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
				& (1 << port))
			removable = false;
	} else {
		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
			removable = false;
	}

	if (removable)
		udev->removable = USB_DEVICE_REMOVABLE;
	else
		udev->removable = USB_DEVICE_FIXED;
}

/**
 * usb_new_device - perform initial device setup (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * This is called with devices which have been detected but not fully
 * enumerated.  The device descriptor is available, but not descriptors
 * for any device configuration.  The caller must have locked either
 * the parent hub (if udev is a normal device) or else the
 * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
 * udev has already been installed, but udev is not yet visible through
 * sysfs or other filesystem code.
 *
 * It will return if the device is configured properly or not.  Zero if
 * the interface was registered with the driver core; else a negative
 * errno value.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 *
 * Only the hub driver or root-hub registrar should ever call this.
 */
int usb_new_device(struct usb_device *udev)
{
	int err;

	if (udev->parent) {
		/* Initialize non-root-hub device wakeup to disabled;
		 * device (un)configuration controls wakeup capable
		 * sysfs power/wakeup controls wakeup enabled/disabled
		 */
		device_init_wakeup(&udev->dev, 0);
	}

	/* Tell the runtime-PM framework the device is active */
	pm_runtime_set_active(&udev->dev);
	pm_runtime_get_noresume(&udev->dev);
	pm_runtime_use_autosuspend(&udev->dev);
	pm_runtime_enable(&udev->dev);

	/* By default, forbid autosuspend for all devices.  It will be
	 * allowed for hubs during binding.
	 */
	usb_disable_autosuspend(udev);

	err = usb_enumerate_device(udev);	/* Read descriptors */
	if (err < 0)
		goto fail;
	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
			udev->devnum, udev->bus->busnum,
			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
	/* export the usbdev device-node for libusb */
	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));

	/* Tell the world! */
	announce_device(udev);

	if (udev->serial)
		add_device_randomness(udev->serial, strlen(udev->serial));
	if (udev->product)
		add_device_randomness(udev->product, strlen(udev->product));
	if (udev->manufacturer)
		add_device_randomness(udev->manufacturer,
				      strlen(udev->manufacturer));

	device_enable_async_suspend(&udev->dev);

	/*
	 * check whether the hub marks this port as non-removable. Do it
	 * now so that platform-specific data can override it in
	 * device_add()
	 */
	if (udev->parent)
		set_usb_port_removable(udev);

	/* Register the device.  The device driver is responsible
	 * for configuring the device and invoking the add-device
	 * notifier chain (used by usbfs and possibly others).
	 */
	err = device_add(&udev->dev);
	if (err) {
		dev_err(&udev->dev, "can't device_add, error %d\n", err);
		goto fail;
	}

	/* Create link files between child device and usb port device. */
	if (udev->parent) {
		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
		struct usb_port	*port_dev;

		if (!hub)
			goto fail;

		port_dev = hub->ports[udev->portnum - 1];
		if (!port_dev)
			goto fail;

		err = sysfs_create_link(&udev->dev.kobj,
				&port_dev->dev.kobj, "port");
		if (err)
			goto fail;

		err = sysfs_create_link(&port_dev->dev.kobj,
				&udev->dev.kobj, "device");
		if (err) {
			sysfs_remove_link(&udev->dev.kobj, "port");
			goto fail;
		}

		pm_runtime_get_sync(&port_dev->dev);
	}

	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
	usb_mark_last_busy(udev);
	pm_runtime_put_sync_autosuspend(&udev->dev);
	return err;

fail:
	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
	pm_runtime_disable(&udev->dev);
	pm_runtime_set_suspended(&udev->dev);
	return err;
}


/**
 * usb_deauthorize_device - deauthorize a device (usbcore-internal)
 * @usb_dev: USB device
 *
 * Move the USB device to a very basic state where interfaces are disabled
 * and the device is in fact unconfigured and unusable.
 *
 * We share a lock (that we have) with device_del(), so we need to
 * defer its call.
 */
int usb_deauthorize_device(struct usb_device *usb_dev)
{
	usb_lock_device(usb_dev);
	if (usb_dev->authorized == 0)
		goto out_unauthorized;

	usb_dev->authorized = 0;
	usb_set_configuration(usb_dev, -1);

out_unauthorized:
	usb_unlock_device(usb_dev);
	return 0;
}


int usb_authorize_device(struct usb_device *usb_dev)
{
	int result = 0, c;

	usb_lock_device(usb_dev);
	if (usb_dev->authorized == 1)
		goto out_authorized;

	result = usb_autoresume_device(usb_dev);
	if (result < 0) {
		dev_err(&usb_dev->dev,
			"can't autoresume for authorization: %d\n", result);
		goto error_autoresume;
	}
	result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
	if (result < 0) {
		dev_err(&usb_dev->dev, "can't re-read device descriptor for "
			"authorization: %d\n", result);
		goto error_device_descriptor;
	}

	usb_dev->authorized = 1;
	/* Choose and set the configuration.  This registers the interfaces
	 * with the driver core and lets interface drivers bind to them.
	 */
	c = usb_choose_configuration(usb_dev);
	if (c >= 0) {
		result = usb_set_configuration(usb_dev, c);
		if (result) {
			dev_err(&usb_dev->dev,
				"can't set config #%d, error %d\n", c, result);
			/* This need not be fatal.  The user can try to
			 * set other configurations. */
		}
	}
	dev_info(&usb_dev->dev, "authorized to connect\n");

error_device_descriptor:
	usb_autosuspend_device(usb_dev);
error_autoresume:
out_authorized:
	usb_unlock_device(usb_dev);	// complements locktree
	return result;
}


/* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
static unsigned hub_is_wusb(struct usb_hub *hub)
{
	struct usb_hcd *hcd;
	if (hub->hdev->parent != NULL)  /* not a root hub? */
		return 0;
	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
	return hcd->wireless;
}


#define PORT_RESET_TRIES	5
#define SET_ADDRESS_TRIES	2
#define GET_DESCRIPTOR_TRIES	2
#define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
#define USE_NEW_SCHEME(i)	((i) / 2 == (int)old_scheme_first)

#define HUB_ROOT_RESET_TIME	50	/* times are in msec */
#define HUB_SHORT_RESET_TIME	10
#define HUB_BH_RESET_TIME	50
#define HUB_LONG_RESET_TIME	200
#define HUB_RESET_TIMEOUT	800

static int hub_port_reset(struct usb_hub *hub, int port1,
			struct usb_device *udev, unsigned int delay, bool warm);

/* Is a USB 3.0 port in the Inactive or Complinance Mode state?
 * Port worm reset is required to recover
 */
static bool hub_port_warm_reset_required(struct usb_hub *hub, u16 portstatus)
{
	return hub_is_superspeed(hub->hdev) &&
		(((portstatus & USB_PORT_STAT_LINK_STATE) ==
		  USB_SS_PORT_LS_SS_INACTIVE) ||
		 ((portstatus & USB_PORT_STAT_LINK_STATE) ==
		  USB_SS_PORT_LS_COMP_MOD)) ;
}

static int hub_port_wait_reset(struct usb_hub *hub, int port1,
			struct usb_device *udev, unsigned int delay, bool warm)
{
	int delay_time, ret;
	u16 portstatus;
	u16 portchange;

	for (delay_time = 0;
			delay_time < HUB_RESET_TIMEOUT;
			delay_time += delay) {
		/* wait to give the device a chance to reset */
		msleep(delay);

		/* read and decode port status */
		ret = hub_port_status(hub, port1, &portstatus, &portchange);
		if (ret < 0)
			return ret;

		/* The port state is unknown until the reset completes. */
		if (!(portstatus & USB_PORT_STAT_RESET))
			break;

		/* switch to the long delay after two short delay failures */
		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
			delay = HUB_LONG_RESET_TIME;

		dev_dbg (hub->intfdev,
			"port %d not %sreset yet, waiting %dms\n",
			port1, warm ? "warm " : "", delay);
	}

	if ((portstatus & USB_PORT_STAT_RESET))
		return -EBUSY;

	if (hub_port_warm_reset_required(hub, portstatus))
		return -ENOTCONN;

	/* Device went away? */
	if (!(portstatus & USB_PORT_STAT_CONNECTION))
		return -ENOTCONN;

	/* bomb out completely if the connection bounced.  A USB 3.0
	 * connection may bounce if multiple warm resets were issued,
	 * but the device may have successfully re-connected. Ignore it.
	 */
	if (!hub_is_superspeed(hub->hdev) &&
			(portchange & USB_PORT_STAT_C_CONNECTION))
		return -ENOTCONN;

	if (!(portstatus & USB_PORT_STAT_ENABLE))
		return -EBUSY;

	if (!udev)
		return 0;

	if (hub_is_wusb(hub))
		udev->speed = USB_SPEED_WIRELESS;
	else if (hub_is_superspeed(hub->hdev))
		udev->speed = USB_SPEED_SUPER;
	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
		udev->speed = USB_SPEED_HIGH;
	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
		udev->speed = USB_SPEED_LOW;
	else
		udev->speed = USB_SPEED_FULL;
	return 0;
}

static void hub_port_finish_reset(struct usb_hub *hub, int port1,
			struct usb_device *udev, int *status)
{
	switch (*status) {
	case 0:
		/* TRSTRCY = 10 ms; plus some extra */
		msleep(10 + 40);
		if (udev) {
			struct usb_hcd *hcd = bus_to_hcd(udev->bus);

			update_devnum(udev, 0);
			/* The xHC may think the device is already reset,
			 * so ignore the status.
			 */
			if (hcd->driver->reset_device)
				hcd->driver->reset_device(hcd, udev);
		}
		/* FALL THROUGH */
	case -ENOTCONN:
	case -ENODEV:
		usb_clear_port_feature(hub->hdev,
				port1, USB_PORT_FEAT_C_RESET);
		if (hub_is_superspeed(hub->hdev)) {
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_BH_PORT_RESET);
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_PORT_LINK_STATE);
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		}
		if (udev)
			usb_set_device_state(udev, *status
					? USB_STATE_NOTATTACHED
					: USB_STATE_DEFAULT);
		break;
	}
}

/* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
static int hub_port_reset(struct usb_hub *hub, int port1,
			struct usb_device *udev, unsigned int delay, bool warm)
{
	int i, status;
	u16 portchange, portstatus;

	if (!hub_is_superspeed(hub->hdev)) {
		if (warm) {
			dev_err(hub->intfdev, "only USB3 hub support "
						"warm reset\n");
			return -EINVAL;
		}
		/* Block EHCI CF initialization during the port reset.
		 * Some companion controllers don't like it when they mix.
		 */
		down_read(&ehci_cf_port_reset_rwsem);
	} else if (!warm) {
		/*
		 * If the caller hasn't explicitly requested a warm reset,
		 * double check and see if one is needed.
		 */
		status = hub_port_status(hub, port1,
					&portstatus, &portchange);
		if (status < 0)
			goto done;

		if (hub_port_warm_reset_required(hub, portstatus))
			warm = true;
	}

	/* Reset the port */
	for (i = 0; i < PORT_RESET_TRIES; i++) {
		status = set_port_feature(hub->hdev, port1, (warm ?
					USB_PORT_FEAT_BH_PORT_RESET :
					USB_PORT_FEAT_RESET));
		if (status == -ENODEV) {
			;	/* The hub is gone */
		} else if (status) {
			dev_err(hub->intfdev,
					"cannot %sreset port %d (err = %d)\n",
					warm ? "warm " : "", port1, status);
		} else {
			status = hub_port_wait_reset(hub, port1, udev, delay,
								warm);
			if (status && status != -ENOTCONN && status != -ENODEV)
				dev_dbg(hub->intfdev,
						"port_wait_reset: err = %d\n",
						status);
		}

		/* Check for disconnect or reset */
		if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
			hub_port_finish_reset(hub, port1, udev, &status);

			if (!hub_is_superspeed(hub->hdev))
				goto done;

			/*
			 * If a USB 3.0 device migrates from reset to an error
			 * state, re-issue the warm reset.
			 */
			if (hub_port_status(hub, port1,
					&portstatus, &portchange) < 0)
				goto done;

			if (!hub_port_warm_reset_required(hub, portstatus))
				goto done;

			/*
			 * If the port is in SS.Inactive or Compliance Mode, the
			 * hot or warm reset failed.  Try another warm reset.
			 */
			if (!warm) {
				dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
						port1);
				warm = true;
			}
		}

		dev_dbg (hub->intfdev,
			"port %d not enabled, trying %sreset again...\n",
			port1, warm ? "warm " : "");
		delay = HUB_LONG_RESET_TIME;
	}

	dev_err (hub->intfdev,
		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
		port1);

done:
	if (!hub_is_superspeed(hub->hdev))
		up_read(&ehci_cf_port_reset_rwsem);

	return status;
}

/* Check if a port is power on */
static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
{
	int ret = 0;

	if (hub_is_superspeed(hub->hdev)) {
		if (portstatus & USB_SS_PORT_STAT_POWER)
			ret = 1;
	} else {
		if (portstatus & USB_PORT_STAT_POWER)
			ret = 1;
	}

	return ret;
}

#ifdef	CONFIG_PM

/* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
{
	int ret = 0;

	if (hub_is_superspeed(hub->hdev)) {
		if ((portstatus & USB_PORT_STAT_LINK_STATE)
				== USB_SS_PORT_LS_U3)
			ret = 1;
	} else {
		if (portstatus & USB_PORT_STAT_SUSPEND)
			ret = 1;
	}

	return ret;
}

/* Determine whether the device on a port is ready for a normal resume,
 * is ready for a reset-resume, or should be disconnected.
 */
static int check_port_resume_type(struct usb_device *udev,
		struct usb_hub *hub, int port1,
		int status, unsigned portchange, unsigned portstatus)
{
	/* Is the device still present? */
	if (status || port_is_suspended(hub, portstatus) ||
			!port_is_power_on(hub, portstatus) ||
			!(portstatus & USB_PORT_STAT_CONNECTION)) {
		if (status >= 0)
			status = -ENODEV;
	}

	/* Can't do a normal resume if the port isn't enabled,
	 * so try a reset-resume instead.
	 */
	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
		if (udev->persist_enabled)
			udev->reset_resume = 1;
		else
			status = -ENODEV;
	}

	if (status) {
		dev_dbg(hub->intfdev,
				"port %d status %04x.%04x after resume, %d\n",
				port1, portchange, portstatus, status);
	} else if (udev->reset_resume) {

		/* Late port handoff can set status-change bits */
		if (portchange & USB_PORT_STAT_C_CONNECTION)
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		if (portchange & USB_PORT_STAT_C_ENABLE)
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_ENABLE);
	}

	return status;
}

int usb_disable_ltm(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	/* Check if the roothub and device supports LTM. */
	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
			!usb_device_supports_ltm(udev))
		return 0;

	/* Clear Feature LTM Enable can only be sent if the device is
	 * configured.
	 */
	if (!udev->actconfig)
		return 0;

	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
			USB_CTRL_SET_TIMEOUT);
}
EXPORT_SYMBOL_GPL(usb_disable_ltm);

void usb_enable_ltm(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	/* Check if the roothub and device supports LTM. */
	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
			!usb_device_supports_ltm(udev))
		return;

	/* Set Feature LTM Enable can only be sent if the device is
	 * configured.
	 */
	if (!udev->actconfig)
		return;

	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
			USB_CTRL_SET_TIMEOUT);
}
EXPORT_SYMBOL_GPL(usb_enable_ltm);

#ifdef	CONFIG_PM
/*
 * usb_disable_function_remotewakeup - disable usb3.0
 * device's function remote wakeup
 * @udev: target device
 *
 * Assume there's only one function on the USB 3.0
 * device and disable remote wake for the first
 * interface. FIXME if the interface association
 * descriptor shows there's more than one function.
 */
static int usb_disable_function_remotewakeup(struct usb_device *udev)
{
	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
				USB_CTRL_SET_TIMEOUT);
}

/* Count of wakeup-enabled devices at or below udev */
static unsigned wakeup_enabled_descendants(struct usb_device *udev)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(udev);

	return udev->do_remote_wakeup +
			(hub ? hub->wakeup_enabled_descendants : 0);
}

/*
 * usb_port_suspend - suspend a usb device's upstream port
 * @udev: device that's no longer in active use, not a root hub
 * Context: must be able to sleep; device not locked; pm locks held
 *
 * Suspends a USB device that isn't in active use, conserving power.
 * Devices may wake out of a suspend, if anything important happens,
 * using the remote wakeup mechanism.  They may also be taken out of
 * suspend by the host, using usb_port_resume().  It's also routine
 * to disconnect devices while they are suspended.
 *
 * This only affects the USB hardware for a device; its interfaces
 * (and, for hubs, child devices) must already have been suspended.
 *
 * Selective port suspend reduces power; most suspended devices draw
 * less than 500 uA.  It's also used in OTG, along with remote wakeup.
 * All devices below the suspended port are also suspended.
 *
 * Devices leave suspend state when the host wakes them up.  Some devices
 * also support "remote wakeup", where the device can activate the USB
 * tree above them to deliver data, such as a keypress or packet.  In
 * some cases, this wakes the USB host.
 *
 * Suspending OTG devices may trigger HNP, if that's been enabled
 * between a pair of dual-role devices.  That will change roles, such
 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
 *
 * Devices on USB hub ports have only one "suspend" state, corresponding
 * to ACPI D2, "may cause the device to lose some context".
 * State transitions include:
 *
 *   - suspend, resume ... when the VBUS power link stays live
 *   - suspend, disconnect ... VBUS lost
 *
 * Once VBUS drop breaks the circuit, the port it's using has to go through
 * normal re-enumeration procedures, starting with enabling VBUS power.
 * Other than re-initializing the hub (plug/unplug, except for root hubs),
 * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
 * timer, no SRP, no requests through sysfs.
 *
 * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
 * suspended until their bus goes into global suspend (i.e., the root
 * hub is suspended).  Nevertheless, we change @udev->state to
 * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
 * upstream port setting is stored in @udev->port_is_suspended.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
{
	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
	struct usb_port *port_dev;
	int		port1 = udev->portnum;
	int		status;
	bool		really_suspend = true;

	if (!hub)
		return -ENODEV;

	port_dev = hub->ports[udev->portnum - 1];
	/* enable remote wakeup when appropriate; this lets the device
	 * wake up the upstream hub (including maybe the root hub).
	 *
	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
	 * we don't explicitly enable it here.
	 */
	if (udev->do_remote_wakeup) {
		if (!hub_is_superspeed(hub->hdev)) {
			status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
					USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
					USB_DEVICE_REMOTE_WAKEUP, 0,
					NULL, 0,
					USB_CTRL_SET_TIMEOUT);
		} else {
			/* Assume there's only one function on the USB 3.0
			 * device and enable remote wake for the first
			 * interface. FIXME if the interface association
			 * descriptor shows there's more than one function.
			 */
			status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
					USB_REQ_SET_FEATURE,
					USB_RECIP_INTERFACE,
					USB_INTRF_FUNC_SUSPEND,
					USB_INTRF_FUNC_SUSPEND_RW |
					USB_INTRF_FUNC_SUSPEND_LP,
					NULL, 0,
					USB_CTRL_SET_TIMEOUT);
		}
		if (status) {
			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
					status);
			/* bail if autosuspend is requested */
			if (PMSG_IS_AUTO(msg))
				goto err_wakeup;
		}
	}
#ifdef CONFIG_USB_OTG
	if (!udev->bus->is_b_host && udev->bus->hnp_support &&
		udev->portnum == udev->bus->otg_port) {
		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_SET_FEATURE, 0,
				USB_DEVICE_B_HNP_ENABLE,
				0, NULL, 0, USB_CTRL_SET_TIMEOUT);
		if (status < 0) {
			otg_send_event(OTG_EVENT_NO_RESP_FOR_HNP_ENABLE);
			dev_dbg(&udev->dev, "can't enable HNP on port %d, "
					"status %d\n", port1, status);
		} else {
			udev->bus->b_hnp_enable = 1;
		}
	}
#endif

	/* disable USB2 hardware LPM */
	if (udev->usb2_hw_lpm_enabled == 1)
		usb_set_usb2_hardware_lpm(udev, 0);

	if (usb_disable_ltm(udev)) {
		dev_err(&udev->dev, "Failed to disable LTM before suspend\n.");
		status = -ENOMEM;
		if (PMSG_IS_AUTO(msg))
			goto err_ltm;
	}
	if (usb_unlocked_disable_lpm(udev)) {
		dev_err(&udev->dev, "Failed to disable LPM before suspend\n.");
		status = -ENOMEM;
		if (PMSG_IS_AUTO(msg))
			goto err_lpm3;
	}

	/* see 7.1.7.6 */
	if (hub_is_superspeed(hub->hdev))
		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);

	/*
	 * For system suspend, we do not need to enable the suspend feature
	 * on individual USB-2 ports.  The devices will automatically go
	 * into suspend a few ms after the root hub stops sending packets.
	 * The USB 2.0 spec calls this "global suspend".
	 *
	 * However, many USB hubs have a bug: They don't relay wakeup requests
	 * from a downstream port if the port's suspend feature isn't on.
	 * Therefore we will turn on the suspend feature if udev or any of its
	 * descendants is enabled for remote wakeup.
	 */
	else if (PMSG_IS_AUTO(msg) || wakeup_enabled_descendants(udev) > 0)
		status = set_port_feature(hub->hdev, port1,
				USB_PORT_FEAT_SUSPEND);
	else {
		really_suspend = false;
		status = 0;
	}
	if (status) {
		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
				port1, status);

		/* Try to enable USB3 LPM and LTM again */
		usb_unlocked_enable_lpm(udev);
 err_lpm3:
		usb_enable_ltm(udev);
 err_ltm:
		/* Try to enable USB2 hardware LPM again */
		if (udev->usb2_hw_lpm_capable == 1)
			usb_set_usb2_hardware_lpm(udev, 1);

		if (udev->do_remote_wakeup) {
			if (udev->speed < USB_SPEED_SUPER)
				usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
						USB_REQ_CLEAR_FEATURE,
						USB_RECIP_DEVICE,
						USB_DEVICE_REMOTE_WAKEUP, 0,
						NULL, 0, USB_CTRL_SET_TIMEOUT);
			else
				usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
						USB_REQ_CLEAR_FEATURE,
						USB_RECIP_INTERFACE,
						USB_INTRF_FUNC_SUSPEND, 0,
						NULL, 0, USB_CTRL_SET_TIMEOUT);
		}
 err_wakeup:

		/* System sleep transitions should never fail */
		if (!PMSG_IS_AUTO(msg))
			status = 0;
	} else {
		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
				udev->do_remote_wakeup);
		if (really_suspend) {
			udev->port_is_suspended = 1;

			/* device has up to 10 msec to fully suspend */
			msleep(10);
		}
		usb_set_device_state(udev, USB_STATE_SUSPENDED);
	}

	if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled) {
		pm_runtime_put_sync(&port_dev->dev);
		port_dev->did_runtime_put = true;
	}

	usb_mark_last_busy(hub->hdev);
	return status;
}

/*
 * If the USB "suspend" state is in use (rather than "global suspend"),
 * many devices will be individually taken out of suspend state using
 * special "resume" signaling.  This routine kicks in shortly after
 * hardware resume signaling is finished, either because of selective
 * resume (by host) or remote wakeup (by device) ... now see what changed
 * in the tree that's rooted at this device.
 *
 * If @udev->reset_resume is set then the device is reset before the
 * status check is done.
 */
static int finish_port_resume(struct usb_device *udev)
{
	int	status = 0;
	u16	devstatus = 0;

	/* caller owns the udev device lock */
	dev_dbg(&udev->dev, "%s\n",
		udev->reset_resume ? "finish reset-resume" : "finish resume");

	/* usb ch9 identifies four variants of SUSPENDED, based on what
	 * state the device resumes to.  Linux currently won't see the
	 * first two on the host side; they'd be inside hub_port_init()
	 * during many timeouts, but khubd can't suspend until later.
	 */
	usb_set_device_state(udev, udev->actconfig
			? USB_STATE_CONFIGURED
			: USB_STATE_ADDRESS);

	/* 10.5.4.5 says not to reset a suspended port if the attached
	 * device is enabled for remote wakeup.  Hence the reset
	 * operation is carried out here, after the port has been
	 * resumed.
	 */
	if (udev->reset_resume)
 retry_reset_resume:
		status = usb_reset_and_verify_device(udev);

 	/* 10.5.4.5 says be sure devices in the tree are still there.
 	 * For now let's assume the device didn't go crazy on resume,
	 * and device drivers will know about any resume quirks.
	 */
	if (status == 0) {
		devstatus = 0;
		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
		if (status >= 0)
			status = (status > 0 ? 0 : -ENODEV);

		/* If a normal resume failed, try doing a reset-resume */
		if (status && !udev->reset_resume && udev->persist_enabled) {
			dev_dbg(&udev->dev, "retry with reset-resume\n");
			udev->reset_resume = 1;
			goto retry_reset_resume;
		}
	}

	if (status) {
		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
				status);
	/*
	 * There are a few quirky devices which violate the standard
	 * by claiming to have remote wakeup enabled after a reset,
	 * which crash if the feature is cleared, hence check for
	 * udev->reset_resume
	 */
	} else if (udev->actconfig && !udev->reset_resume) {
		if (!hub_is_superspeed(udev->parent)) {
			le16_to_cpus(&devstatus);
			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
				status = usb_control_msg(udev,
						usb_sndctrlpipe(udev, 0),
						USB_REQ_CLEAR_FEATURE,
						USB_RECIP_DEVICE,
						USB_DEVICE_REMOTE_WAKEUP, 0,
						NULL, 0,
						USB_CTRL_SET_TIMEOUT);
		} else {
			status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
					&devstatus);
			le16_to_cpus(&devstatus);
			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
					| USB_INTRF_STAT_FUNC_RW))
				status =
					usb_disable_function_remotewakeup(udev);
		}

		if (status)
			dev_dbg(&udev->dev,
				"disable remote wakeup, status %d\n",
				status);
		status = 0;
	}
	return status;
}

/*
 * There are some SS USB devices which take longer time for link training.
 * XHCI specs 4.19.4 says that when Link training is successful, port
 * sets CSC bit to 1. So if SW reads port status before successful link
 * training, then it will not find device to be present.
 * USB Analyzer log with such buggy devices show that in some cases
 * device switch on the RX termination after long delay of host enabling
 * the VBUS. In few other cases it has been seen that device fails to
 * negotiate link training in first attempt. It has been
 * reported till now that few devices take as long as 2000 ms to train
 * the link after host enabling its VBUS and termination. Following
 * routine implements a 2000 ms timeout for link training. If in a case
 * link trains before timeout, loop will exit earlier.
 *
 * FIXME: If a device was connected before suspend, but was removed
 * while system was asleep, then the loop in the following routine will
 * only exit at timeout.
 *
 * This routine should only be called when persist is enabled for a SS
 * device.
 */
static int wait_for_ss_port_enable(struct usb_device *udev,
		struct usb_hub *hub, int *port1,
		u16 *portchange, u16 *portstatus)
{
	int status = 0, delay_ms = 0;

	while (delay_ms < 2000) {
		if (status || *portstatus & USB_PORT_STAT_CONNECTION)
			break;
		msleep(20);
		delay_ms += 20;
		status = hub_port_status(hub, *port1, portstatus, portchange);
	}
	return status;
}

/*
 * usb_port_resume - re-activate a suspended usb device's upstream port
 * @udev: device to re-activate, not a root hub
 * Context: must be able to sleep; device not locked; pm locks held
 *
 * This will re-activate the suspended device, increasing power usage
 * while letting drivers communicate again with its endpoints.
 * USB resume explicitly guarantees that the power session between
 * the host and the device is the same as it was when the device
 * suspended.
 *
 * If @udev->reset_resume is set then this routine won't check that the
 * port is still enabled.  Furthermore, finish_port_resume() above will
 * reset @udev.  The end result is that a broken power session can be
 * recovered and @udev will appear to persist across a loss of VBUS power.
 *
 * For example, if a host controller doesn't maintain VBUS suspend current
 * during a system sleep or is reset when the system wakes up, all the USB
 * power sessions below it will be broken.  This is especially troublesome
 * for mass-storage devices containing mounted filesystems, since the
 * device will appear to have disconnected and all the memory mappings
 * to it will be lost.  Using the USB_PERSIST facility, the device can be
 * made to appear as if it had not disconnected.
 *
 * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
 * every effort to insure that the same device is present after the
 * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
 * quite possible for a device to remain unaltered but its media to be
 * changed.  If the user replaces a flash memory card while the system is
 * asleep, he will have only himself to blame when the filesystem on the
 * new card is corrupted and the system crashes.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_port_resume(struct usb_device *udev, pm_message_t msg)
{
	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
	struct usb_port *port_dev;
	int		port1 = udev->portnum;
	int		status;
	u16		portchange, portstatus;

	if (!hub)
		return -ENODEV;

	port_dev = hub->ports[udev->portnum - 1];
	if (port_dev->did_runtime_put) {
		status = pm_runtime_get_sync(&port_dev->dev);
		port_dev->did_runtime_put = false;
		if (status < 0) {
			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
					status);
			return status;
		}
	}

	/* Skip the initial Clear-Suspend step for a remote wakeup */
	status = hub_port_status(hub, port1, &portstatus, &portchange);
	if (status == 0 && !port_is_suspended(hub, portstatus))
		goto SuspendCleared;

	// dev_dbg(hub->intfdev, "resume port %d\n", port1);

	set_bit(port1, hub->busy_bits);

	/* see 7.1.7.7; affects power usage, but not budgeting */
	if (hub_is_superspeed(hub->hdev))
		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
	else
		status = usb_clear_port_feature(hub->hdev,
				port1, USB_PORT_FEAT_SUSPEND);
	if (status) {
		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
				port1, status);
	} else {
		/* drive resume for USB_RESUME_TIMEOUT msec */
		dev_dbg(&udev->dev, "usb %sresume\n",
				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
		msleep(USB_RESUME_TIMEOUT);

		/* Virtual root hubs can trigger on GET_PORT_STATUS to
		 * stop resume signaling.  Then finish the resume
		 * sequence.
		 */
		status = hub_port_status(hub, port1, &portstatus, &portchange);

		/* TRSMRCY = 10 msec */
		msleep(10);
	}

 SuspendCleared:
	if (status == 0) {
		udev->port_is_suspended = 0;
		if (hub_is_superspeed(hub->hdev)) {
			if (portchange & USB_PORT_STAT_C_LINK_STATE)
				usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_PORT_LINK_STATE);
		} else {
			if (portchange & USB_PORT_STAT_C_SUSPEND)
				usb_clear_port_feature(hub->hdev, port1,
						USB_PORT_FEAT_C_SUSPEND);
		}
	}

	clear_bit(port1, hub->busy_bits);

	if (udev->persist_enabled && hub_is_superspeed(hub->hdev))
		status = wait_for_ss_port_enable(udev, hub, &port1, &portchange,
				&portstatus);

	status = check_port_resume_type(udev,
			hub, port1, status, portchange, portstatus);
	if (status == 0)
		status = finish_port_resume(udev);
	if (status < 0) {
		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
		hub_port_logical_disconnect(hub, port1);
	} else  {
		/* Try to enable USB2 hardware LPM */
		if (udev->usb2_hw_lpm_capable == 1)
			usb_set_usb2_hardware_lpm(udev, 1);

		/* Try to enable USB3 LTM and LPM */
		usb_enable_ltm(udev);
		usb_unlocked_enable_lpm(udev);
	}

	return status;
}

#endif	/* CONFIG_PM */

#ifdef	CONFIG_PM_RUNTIME

/* caller has locked udev */
int usb_remote_wakeup(struct usb_device *udev)
{
	int	status = 0;
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	if (udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
		status = usb_autoresume_device(udev);
		if (status == 0) {
			/* Let the drivers do their thing, then... */
			usb_autosuspend_device(udev);
		}
	} else {
		dev_dbg(&udev->dev, "usb not suspended\n");
		clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
	}

	return status;
}

#endif

static int check_ports_changed(struct usb_hub *hub)
{
	int port1;

	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
		u16 portstatus, portchange;
		int status;

		status = hub_port_status(hub, port1, &portstatus, &portchange);
		if (!status && portchange)
			return 1;
	}
	return 0;
}

static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
{
	struct usb_hub		*hub = usb_get_intfdata (intf);
	struct usb_device	*hdev = hub->hdev;
	unsigned		port1;
	int			status;

	/*
	 * Warn if children aren't already suspended.
	 * Also, add up the number of wakeup-enabled descendants.
	 */
	hub->wakeup_enabled_descendants = 0;
	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
		struct usb_device	*udev;

		udev = hub->ports[port1 - 1]->child;
		if (udev && udev->can_submit) {
			dev_warn(&intf->dev, "port %d nyet suspended\n", port1);
			if (PMSG_IS_AUTO(msg))
				return -EBUSY;
		}
		if (udev)
			hub->wakeup_enabled_descendants +=
					wakeup_enabled_descendants(udev);
	}

	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
		/* check if there are changes pending on hub ports */
		if (check_ports_changed(hub)) {
			if (PMSG_IS_AUTO(msg))
				return -EBUSY;
			pm_wakeup_event(&hdev->dev, 2000);
		}
	}

	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
		/* Enable hub to send remote wakeup for all ports. */
		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
			status = set_port_feature(hdev,
					port1 |
					USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
					USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
					USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
					USB_PORT_FEAT_REMOTE_WAKE_MASK);
		}
	}

	dev_dbg(&intf->dev, "%s\n", __func__);

	/* stop khubd and related activity */
	hub_quiesce(hub, HUB_SUSPEND);
	return 0;
}

static int hub_resume(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	dev_dbg(&intf->dev, "%s\n", __func__);
	hub_activate(hub, HUB_RESUME);
	return 0;
}

static int hub_reset_resume(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	dev_dbg(&intf->dev, "%s\n", __func__);
	hub_activate(hub, HUB_RESET_RESUME);
	return 0;
}

/**
 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
 * @rhdev: struct usb_device for the root hub
 *
 * The USB host controller driver calls this function when its root hub
 * is resumed and Vbus power has been interrupted or the controller
 * has been reset.  The routine marks @rhdev as having lost power.
 * When the hub driver is resumed it will take notice and carry out
 * power-session recovery for all the "USB-PERSIST"-enabled child devices;
 * the others will be disconnected.
 */
void usb_root_hub_lost_power(struct usb_device *rhdev)
{
	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
	rhdev->reset_resume = 1;
}
EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);

static const char * const usb3_lpm_names[]  = {
	"U0",
	"U1",
	"U2",
	"U3",
};

/*
 * Send a Set SEL control transfer to the device, prior to enabling
 * device-initiated U1 or U2.  This lets the device know the exit latencies from
 * the time the device initiates a U1 or U2 exit, to the time it will receive a
 * packet from the host.
 *
 * This function will fail if the SEL or PEL values for udev are greater than
 * the maximum allowed values for the link state to be enabled.
 */
static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
{
	struct usb_set_sel_req *sel_values;
	unsigned long long u1_sel;
	unsigned long long u1_pel;
	unsigned long long u2_sel;
	unsigned long long u2_pel;
	int ret;

	/* Convert SEL and PEL stored in ns to us */
	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);

	/*
	 * Make sure that the calculated SEL and PEL values for the link
	 * state we're enabling aren't bigger than the max SEL/PEL
	 * value that will fit in the SET SEL control transfer.
	 * Otherwise the device would get an incorrect idea of the exit
	 * latency for the link state, and could start a device-initiated
	 * U1/U2 when the exit latencies are too high.
	 */
	if ((state == USB3_LPM_U1 &&
				(u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
				 u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) ||
			(state == USB3_LPM_U2 &&
			 (u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
			  u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) {
		dev_dbg(&udev->dev, "Device-initiated %s disabled due to long SEL %llu us or PEL %llu us\n",
				usb3_lpm_names[state], u1_sel, u1_pel);
		return -EINVAL;
	}

	/*
	 * If we're enabling device-initiated LPM for one link state,
	 * but the other link state has a too high SEL or PEL value,
	 * just set those values to the max in the Set SEL request.
	 */
	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL)
		u1_sel = USB3_LPM_MAX_U1_SEL_PEL;

	if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL)
		u1_pel = USB3_LPM_MAX_U1_SEL_PEL;

	if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL)
		u2_sel = USB3_LPM_MAX_U2_SEL_PEL;

	if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
		u2_pel = USB3_LPM_MAX_U2_SEL_PEL;

	/*
	 * usb_enable_lpm() can be called as part of a failed device reset,
	 * which may be initiated by an error path of a mass storage driver.
	 * Therefore, use GFP_NOIO.
	 */
	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
	if (!sel_values)
		return -ENOMEM;

	sel_values->u1_sel = u1_sel;
	sel_values->u1_pel = u1_pel;
	sel_values->u2_sel = cpu_to_le16(u2_sel);
	sel_values->u2_pel = cpu_to_le16(u2_pel);

	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_SET_SEL,
			USB_RECIP_DEVICE,
			0, 0,
			sel_values, sizeof *(sel_values),
			USB_CTRL_SET_TIMEOUT);
	kfree(sel_values);
	return ret;
}

/*
 * Enable or disable device-initiated U1 or U2 transitions.
 */
static int usb_set_device_initiated_lpm(struct usb_device *udev,
		enum usb3_link_state state, bool enable)
{
	int ret;
	int feature;

	switch (state) {
	case USB3_LPM_U1:
		feature = USB_DEVICE_U1_ENABLE;
		break;
	case USB3_LPM_U2:
		feature = USB_DEVICE_U2_ENABLE;
		break;
	default:
		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
				__func__, enable ? "enable" : "disable");
		return -EINVAL;
	}

	if (udev->state != USB_STATE_CONFIGURED) {
		dev_dbg(&udev->dev, "%s: Can't %s %s state "
				"for unconfigured device.\n",
				__func__, enable ? "enable" : "disable",
				usb3_lpm_names[state]);
		return 0;
	}

	if (enable) {
		/*
		 * Now send the control transfer to enable device-initiated LPM
		 * for either U1 or U2.
		 */
		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_SET_FEATURE,
				USB_RECIP_DEVICE,
				feature,
				0, NULL, 0,
				USB_CTRL_SET_TIMEOUT);
	} else {
		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_CLEAR_FEATURE,
				USB_RECIP_DEVICE,
				feature,
				0, NULL, 0,
				USB_CTRL_SET_TIMEOUT);
	}
	if (ret < 0) {
		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
				enable ? "Enable" : "Disable",
				usb3_lpm_names[state]);
		return -EBUSY;
	}
	return 0;
}

static int usb_set_lpm_timeout(struct usb_device *udev,
		enum usb3_link_state state, int timeout)
{
	int ret;
	int feature;

	switch (state) {
	case USB3_LPM_U1:
		feature = USB_PORT_FEAT_U1_TIMEOUT;
		break;
	case USB3_LPM_U2:
		feature = USB_PORT_FEAT_U2_TIMEOUT;
		break;
	default:
		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
				__func__);
		return -EINVAL;
	}

	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
			timeout != USB3_LPM_DEVICE_INITIATED) {
		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
				"which is a reserved value.\n",
				usb3_lpm_names[state], timeout);
		return -EINVAL;
	}

	ret = set_port_feature(udev->parent,
			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
			feature);
	if (ret < 0) {
		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
				"error code %i\n", usb3_lpm_names[state],
				timeout, ret);
		return -EBUSY;
	}
	if (state == USB3_LPM_U1)
		udev->u1_params.timeout = timeout;
	else
		udev->u2_params.timeout = timeout;
	return 0;
}

/*
 * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
 * U1/U2 entry.
 *
 * We will attempt to enable U1 or U2, but there are no guarantees that the
 * control transfers to set the hub timeout or enable device-initiated U1/U2
 * will be successful.
 *
 * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
 * driver know about it.  If that call fails, it should be harmless, and just
 * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
 */
static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
		enum usb3_link_state state)
{
	int timeout, ret;
	__u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
	__le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;

	/* If the device says it doesn't have *any* exit latency to come out of
	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
	 * state.
	 */
	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
			(state == USB3_LPM_U2 && u2_mel == 0))
		return;

	/*
	 * First, let the device know about the exit latencies
	 * associated with the link state we're about to enable.
	 */
	ret = usb_req_set_sel(udev, state);
	if (ret < 0) {
		dev_warn(&udev->dev, "Set SEL for device-initiated %s failed.\n",
				usb3_lpm_names[state]);
		return;
	}

	/* We allow the host controller to set the U1/U2 timeout internally
	 * first, so that it can change its schedule to account for the
	 * additional latency to send data to a device in a lower power
	 * link state.
	 */
	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);

	/* xHCI host controller doesn't want to enable this LPM state. */
	if (timeout == 0)
		return;

	if (timeout < 0) {
		dev_warn(&udev->dev, "Could not enable %s link state, "
				"xHCI error %i.\n", usb3_lpm_names[state],
				timeout);
		return;
	}

	if (usb_set_lpm_timeout(udev, state, timeout))
		/* If we can't set the parent hub U1/U2 timeout,
		 * device-initiated LPM won't be allowed either, so let the xHCI
		 * host know that this link state won't be enabled.
		 */
		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);

	/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
	else if (udev->actconfig)
		usb_set_device_initiated_lpm(udev, state, true);

}

/*
 * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
 * U1/U2 entry.
 *
 * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
 * If zero is returned, the parent will not allow the link to go into U1/U2.
 *
 * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
 * it won't have an effect on the bus link state because the parent hub will
 * still disallow device-initiated U1/U2 entry.
 *
 * If zero is returned, the xHCI host controller may still think U1/U2 entry is
 * possible.  The result will be slightly more bus bandwidth will be taken up
 * (to account for U1/U2 exit latency), but it should be harmless.
 */
static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
		enum usb3_link_state state)
{
	int feature;

	switch (state) {
	case USB3_LPM_U1:
		feature = USB_PORT_FEAT_U1_TIMEOUT;
		break;
	case USB3_LPM_U2:
		feature = USB_PORT_FEAT_U2_TIMEOUT;
		break;
	default:
		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
				__func__);
		return -EINVAL;
	}

	if (usb_set_lpm_timeout(udev, state, 0))
		return -EBUSY;

	usb_set_device_initiated_lpm(udev, state, false);

	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
				"bus schedule bandwidth may be impacted.\n",
				usb3_lpm_names[state]);
	return 0;
}

/*
 * Disable hub-initiated and device-initiated U1 and U2 entry.
 * Caller must own the bandwidth_mutex.
 *
 * This will call usb_enable_lpm() on failure, which will decrement
 * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
 */
int usb_disable_lpm(struct usb_device *udev)
{
	struct usb_hcd *hcd;

	if (!udev || !udev->parent ||
			udev->speed != USB_SPEED_SUPER ||
			!udev->lpm_capable)
		return 0;

	hcd = bus_to_hcd(udev->bus);
	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
		return 0;

	udev->lpm_disable_count++;
	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
		return 0;

	/* If LPM is enabled, attempt to disable it. */
	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
		goto enable_lpm;
	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
		goto enable_lpm;

	return 0;

enable_lpm:
	usb_enable_lpm(udev);
	return -EBUSY;
}
EXPORT_SYMBOL_GPL(usb_disable_lpm);

/* Grab the bandwidth_mutex before calling usb_disable_lpm() */
int usb_unlocked_disable_lpm(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
	int ret;

	if (!hcd)
		return -EINVAL;

	mutex_lock(hcd->bandwidth_mutex);
	ret = usb_disable_lpm(udev);
	mutex_unlock(hcd->bandwidth_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);

/*
 * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
 * xHCI host policy may prevent U1 or U2 from being enabled.
 *
 * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
 * until the lpm_disable_count drops to zero.  Caller must own the
 * bandwidth_mutex.
 */
void usb_enable_lpm(struct usb_device *udev)
{
	struct usb_hcd *hcd;

	if (!udev || !udev->parent ||
			udev->speed != USB_SPEED_SUPER ||
			!udev->lpm_capable)
		return;

	udev->lpm_disable_count--;
	hcd = bus_to_hcd(udev->bus);
	/* Double check that we can both enable and disable LPM.
	 * Device must be configured to accept set feature U1/U2 timeout.
	 */
	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
			!hcd->driver->disable_usb3_lpm_timeout)
		return;

	if (udev->lpm_disable_count > 0)
		return;

	usb_enable_link_state(hcd, udev, USB3_LPM_U1);
	usb_enable_link_state(hcd, udev, USB3_LPM_U2);
}
EXPORT_SYMBOL_GPL(usb_enable_lpm);

/* Grab the bandwidth_mutex before calling usb_enable_lpm() */
void usb_unlocked_enable_lpm(struct usb_device *udev)
{
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	if (!hcd)
		return;

	mutex_lock(hcd->bandwidth_mutex);
	usb_enable_lpm(udev);
	mutex_unlock(hcd->bandwidth_mutex);
}
EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);


#else	/* CONFIG_PM */

#define hub_suspend		NULL
#define hub_resume		NULL
#define hub_reset_resume	NULL

int usb_disable_lpm(struct usb_device *udev)
{
	return 0;
}
EXPORT_SYMBOL_GPL(usb_disable_lpm);

void usb_enable_lpm(struct usb_device *udev) { }
EXPORT_SYMBOL_GPL(usb_enable_lpm);

int usb_unlocked_disable_lpm(struct usb_device *udev)
{
	return 0;
}
EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);

void usb_unlocked_enable_lpm(struct usb_device *udev) { }
EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);

int usb_disable_ltm(struct usb_device *udev)
{
	return 0;
}
EXPORT_SYMBOL_GPL(usb_disable_ltm);

void usb_enable_ltm(struct usb_device *udev) { }
EXPORT_SYMBOL_GPL(usb_enable_ltm);
#endif


/* USB 2.0 spec, 7.1.7.3 / fig 7-29:
 *
 * Between connect detection and reset signaling there must be a delay
 * of 100ms at least for debounce and power-settling.  The corresponding
 * timer shall restart whenever the downstream port detects a disconnect.
 * 
 * Apparently there are some bluetooth and irda-dongles and a number of
 * low-speed devices for which this debounce period may last over a second.
 * Not covered by the spec - but easy to deal with.
 *
 * This implementation uses a 1500ms total debounce timeout; if the
 * connection isn't stable by then it returns -ETIMEDOUT.  It checks
 * every 25ms for transient disconnects.  When the port status has been
 * unchanged for 100ms it returns the port status.
 */
int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
{
	int ret;
	int total_time, stable_time = 0;
	u16 portchange, portstatus;
	unsigned connection = 0xffff;

	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
		ret = hub_port_status(hub, port1, &portstatus, &portchange);
		if (ret < 0)
			return ret;

		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
			if (!must_be_connected ||
			     (connection == USB_PORT_STAT_CONNECTION))
				stable_time += HUB_DEBOUNCE_STEP;
			if (stable_time >= HUB_DEBOUNCE_STABLE)
				break;
		} else {
			stable_time = 0;
			connection = portstatus & USB_PORT_STAT_CONNECTION;
		}

		if (portchange & USB_PORT_STAT_C_CONNECTION) {
			usb_clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		}

		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
			break;
		msleep(HUB_DEBOUNCE_STEP);
	}

	dev_dbg (hub->intfdev,
		"debounce: port %d: total %dms stable %dms status 0x%x\n",
		port1, total_time, stable_time, portstatus);

	if (stable_time < HUB_DEBOUNCE_STABLE)
		return -ETIMEDOUT;
	return portstatus;
}

void usb_ep0_reinit(struct usb_device *udev)
{
	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
	usb_enable_endpoint(udev, &udev->ep0, true);
}
EXPORT_SYMBOL_GPL(usb_ep0_reinit);

#define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
#define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)

static int hub_set_address(struct usb_device *udev, int devnum)
{
	int retval;
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	/*
	 * The host controller will choose the device address,
	 * instead of the core having chosen it earlier
	 */
	if (!hcd->driver->address_device && devnum <= 1)
		return -EINVAL;
	if (udev->state == USB_STATE_ADDRESS)
		return 0;
	if (udev->state != USB_STATE_DEFAULT)
		return -EINVAL;
	if (hcd->driver->address_device)
		retval = hcd->driver->address_device(hcd, udev);
	else
		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
				USB_REQ_SET_ADDRESS, 0, devnum, 0,
				NULL, 0, USB_CTRL_SET_TIMEOUT);
	if (retval == 0) {
		update_devnum(udev, devnum);
		/* Device now using proper address. */
		usb_set_device_state(udev, USB_STATE_ADDRESS);
		usb_ep0_reinit(udev);
	}
	return retval;
}

/* Reset device, (re)assign address, get device descriptor.
 * Device connection must be stable, no more debouncing needed.
 * Returns device in USB_STATE_ADDRESS, except on error.
 *
 * If this is called for an already-existing device (as part of
 * usb_reset_and_verify_device), the caller must own the device lock.  For a
 * newly detected device that is not accessible through any global
 * pointers, it's not necessary to lock the device.
 */
static int
hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
		int retry_counter)
{
	static DEFINE_MUTEX(usb_address0_mutex);

	struct usb_device	*hdev = hub->hdev;
	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
	int			i, j, retval;
	unsigned		delay = HUB_SHORT_RESET_TIME;
	enum usb_device_speed	oldspeed = udev->speed;
	const char		*speed;
	int			devnum = udev->devnum;

	/* root hub ports have a slightly longer reset period
	 * (from USB 2.0 spec, section 7.1.7.5)
	 */
	if (!hdev->parent) {
		delay = HUB_ROOT_RESET_TIME;
		if (port1 == hdev->bus->otg_port)
			hdev->bus->b_hnp_enable = 0;
	}

	/* Some low speed devices have problems with the quick delay, so */
	/*  be a bit pessimistic with those devices. RHbug #23670 */
	if (oldspeed == USB_SPEED_LOW)
		delay = HUB_LONG_RESET_TIME;

	mutex_lock(&usb_address0_mutex);

	/* Reset the device; full speed may morph to high speed */
	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
	retval = hub_port_reset(hub, port1, udev, delay, false);
	if (retval < 0)		/* error or disconnect */
		goto fail;
	/* success, speed is known */

	retval = -ENODEV;

	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
		dev_dbg(&udev->dev, "device reset changed speed!\n");
		goto fail;
	}
	oldspeed = udev->speed;

	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
	 * it's fixed size except for full speed devices.
	 * For Wireless USB devices, ep0 max packet is always 512 (tho
	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
	 */
	switch (udev->speed) {
	case USB_SPEED_SUPER:
	case USB_SPEED_WIRELESS:	/* fixed at 512 */
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
		break;
	case USB_SPEED_HIGH:		/* fixed at 64 */
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
		break;
	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
		/* to determine the ep0 maxpacket size, try to read
		 * the device descriptor to get bMaxPacketSize0 and
		 * then correct our initial guess.
		 */
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
		break;
	case USB_SPEED_LOW:		/* fixed at 8 */
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
		break;
	default:
		goto fail;
	}

	if (udev->speed == USB_SPEED_WIRELESS)
		speed = "variable speed Wireless";
	else
		speed = usb_speed_string(udev->speed);

	if (udev->speed != USB_SPEED_SUPER)
		dev_info(&udev->dev,
				"%s %s USB device number %d using %s\n",
				(udev->config) ? "reset" : "new", speed,
				devnum, udev->bus->controller->driver->name);

	/* Set up TT records, if needed  */
	if (hdev->tt) {
		udev->tt = hdev->tt;
		udev->ttport = hdev->ttport;
	} else if (udev->speed != USB_SPEED_HIGH
			&& hdev->speed == USB_SPEED_HIGH) {
		if (!hub->tt.hub) {
			dev_err(&udev->dev, "parent hub has no TT\n");
			retval = -EINVAL;
			goto fail;
		}
		udev->tt = &hub->tt;
		udev->ttport = port1;
	}
 
	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
	 * Because device hardware and firmware is sometimes buggy in
	 * this area, and this is how Linux has done it for ages.
	 * Change it cautiously.
	 *
	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
	 * so it may help with some non-standards-compliant devices.
	 * Otherwise we start with SET_ADDRESS and then try to read the
	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
	 * value.
	 */
	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
		if (USE_NEW_SCHEME(retry_counter) &&
			!(hcd->driver->flags & HCD_USB3) &&
			!((hcd->driver->flags & HCD_RT_OLD_ENUM) &&
				!hdev->parent)) {
			struct usb_device_descriptor *buf;
			ushort idvendor;
			int r = 0;

#define GET_DESCRIPTOR_BUFSIZE	64
			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
			if (!buf) {
				retval = -ENOMEM;
				continue;
			}

			/* Retry on all errors; some devices are flakey.
			 * 255 is for WUSB devices, we actually need to use
			 * 512 (WUSB1.0[4.8.1]).
			 */
			for (j = 0; j < 3; ++j) {
				buf->bMaxPacketSize0 = 0;
				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
					USB_DT_DEVICE << 8, 0,
					buf, GET_DESCRIPTOR_BUFSIZE,
					initial_descriptor_timeout);
				switch (buf->bMaxPacketSize0) {
				case 8: case 16: case 32: case 64: case 255:
					if (buf->bDescriptorType ==
							USB_DT_DEVICE) {
						r = 0;
						break;
					}
					/* FALL THROUGH */
				default:
					if (r == 0)
						r = -EPROTO;
					break;
				}
				if (r == 0)
					break;
			}
			udev->descriptor.bMaxPacketSize0 =
					buf->bMaxPacketSize0;
			idvendor = le16_to_cpu(buf->idVendor);
			kfree(buf);

			/*
			 * If it is a HSET Test device, we don't issue a
			 * second reset which results in failure due to
			 * speed change.
			 */
			if (idvendor != 0x1a0a) {
				retval = hub_port_reset(hub, port1, udev,
							 delay, false);
				if (retval < 0)	/* error or disconnect */
					goto fail;
				if (oldspeed != udev->speed) {
					dev_dbg(&udev->dev,
					       "device reset changed speed!\n");
					retval = -ENODEV;
					goto fail;
				}
			}
			if (r) {
				if (r != -ENODEV)
					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
							r);
				retval = -EMSGSIZE;
				continue;
			}
#undef GET_DESCRIPTOR_BUFSIZE
		}

 		/*
 		 * If device is WUSB, we already assigned an
 		 * unauthorized address in the Connect Ack sequence;
 		 * authorization will assign the final address.
 		 */
		if (udev->wusb == 0) {
			for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
				retval = hub_set_address(udev, devnum);
				if (retval >= 0)
					break;
				msleep(200);
			}
			if (retval < 0) {
				if (retval != -ENODEV)
					dev_err(&udev->dev, "device not accepting address %d, error %d\n",
							devnum, retval);
				goto fail;
			}
			if (udev->speed == USB_SPEED_SUPER) {
				devnum = udev->devnum;
				dev_info(&udev->dev,
						"%s SuperSpeed USB device number %d using %s\n",
						(udev->config) ? "reset" : "new",
						devnum, udev->bus->controller->driver->name);
			}

			/* cope with hardware quirkiness:
			 *  - let SET_ADDRESS settle, some device hardware wants it
			 *  - read ep0 maxpacket even for high and low speed,
			 */
			msleep(10);
			if (USE_NEW_SCHEME(retry_counter) &&
				!(hcd->driver->flags & HCD_USB3) &&
				!((hcd->driver->flags & HCD_RT_OLD_ENUM) &&
					!hdev->parent))
				break;
  		}

		retval = usb_get_device_descriptor(udev, 8);
		if (retval < 8) {
			if (retval != -ENODEV)
				dev_err(&udev->dev,
					"device descriptor read/8, error %d\n",
					retval);
			if (retval >= 0)
				retval = -EMSGSIZE;
		} else {
			retval = 0;
			break;
		}
	}
	if (retval)
		goto fail;

	if (hcd->phy && !hdev->parent)
		usb_phy_notify_connect(hcd->phy, udev->speed);

	/*
	 * Some superspeed devices have finished the link training process
	 * and attached to a superspeed hub port, but the device descriptor
	 * got from those devices show they aren't superspeed devices. Warm
	 * reset the port attached by the devices can fix them.
	 */
	if ((udev->speed == USB_SPEED_SUPER) &&
			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
		dev_err(&udev->dev, "got a wrong device descriptor, "
				"warm reset device\n");
		hub_port_reset(hub, port1, udev,
				HUB_BH_RESET_TIME, true);
		retval = -EINVAL;
		goto fail;
	}

	if (udev->descriptor.bMaxPacketSize0 == 0xff ||
			udev->speed == USB_SPEED_SUPER)
		i = 512;
	else
		i = udev->descriptor.bMaxPacketSize0;
	if (usb_endpoint_maxp(&udev->ep0.desc) != i) {
		if (udev->speed == USB_SPEED_LOW ||
				!(i == 8 || i == 16 || i == 32 || i == 64)) {
			dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
			retval = -EMSGSIZE;
			goto fail;
		}
		if (udev->speed == USB_SPEED_FULL)
			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
		else
			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
		usb_ep0_reinit(udev);
	}
  
	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
	if (retval < (signed)sizeof(udev->descriptor)) {
		if (retval != -ENODEV)
			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
					retval);
		if (retval >= 0)
			retval = -ENOMSG;
		goto fail;
	}

	usb_detect_quirks(udev);

	if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
		retval = usb_get_bos_descriptor(udev);
		if (!retval) {
			udev->lpm_capable = usb_device_supports_lpm(udev);
			usb_set_lpm_parameters(udev);
		}
	}

	retval = 0;
	/* notify HCD that we have a device connected and addressed */
	if (hcd->driver->update_device)
		hcd->driver->update_device(hcd, udev);
fail:
	if (retval) {
		hub_port_disable(hub, port1, 0);
		update_devnum(udev, devnum);	/* for disconnect processing */
	}
	mutex_unlock(&usb_address0_mutex);
	return retval;
}

static void
check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
{
	struct usb_qualifier_descriptor	*qual;
	int				status;

	qual = kmalloc (sizeof *qual, GFP_KERNEL);
	if (qual == NULL)
		return;

	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
			qual, sizeof *qual);
	if (status == sizeof *qual) {
		dev_info(&udev->dev, "not running at top speed; "
			"connect to a high speed hub\n");
		/* hub LEDs are probably harder to miss than syslog */
		if (hub->has_indicators) {
			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
			schedule_delayed_work (&hub->leds, 0);
		}
	}
	kfree(qual);
}

static unsigned
hub_power_remaining (struct usb_hub *hub)
{
	struct usb_device *hdev = hub->hdev;
	int remaining;
	int port1;

	if (!hub->limited_power)
		return 0;

	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
		struct usb_device	*udev = hub->ports[port1 - 1]->child;
		int			delta;
		unsigned		unit_load;

		if (!udev)
			continue;
		if (hub_is_superspeed(udev))
			unit_load = 150;
		else
			unit_load = 100;

		/*
		 * Unconfigured devices may not use more than one unit load,
		 * or 8mA for OTG ports
		 */
		if (udev->actconfig)
			delta = usb_get_max_power(udev, udev->actconfig);
		else if (port1 != udev->bus->otg_port || hdev->parent)
			delta = unit_load;
		else
			delta = 8;
		if (delta > hub->mA_per_port)
			dev_warn(&udev->dev,
				 "%dmA is over %umA budget for port %d!\n",
				 delta, hub->mA_per_port, port1);
		remaining -= delta;
	}
	if (remaining < 0) {
		dev_warn(hub->intfdev, "%dmA over power budget!\n",
			- remaining);
		remaining = 0;
	}
	return remaining;
}

/* Handle physical or logical connection change events.
 * This routine is called when:
 * 	a port connection-change occurs;
 *	a port enable-change occurs (often caused by EMI);
 *	usb_reset_and_verify_device() encounters changed descriptors (as from
 *		a firmware download)
 * caller already locked the hub
 */
static void hub_port_connect_change(struct usb_hub *hub, int port1,
					u16 portstatus, u16 portchange)
{
	struct usb_device *hdev = hub->hdev;
	struct device *hub_dev = hub->intfdev;
	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
	unsigned wHubCharacteristics =
			le16_to_cpu(hub->descriptor->wHubCharacteristics);
	struct usb_device *udev;
	int status, i;
	unsigned unit_load;

	dev_dbg (hub_dev,
		"port %d, status %04x, change %04x, %s\n",
		port1, portstatus, portchange, portspeed(hub, portstatus));

	if (hub->has_indicators) {
		set_port_led(hub, port1, HUB_LED_AUTO);
		hub->indicator[port1-1] = INDICATOR_AUTO;
	}

#ifdef	CONFIG_USB_OTG
	/* during HNP, don't repeat the debounce */
	if (hdev->bus->is_b_host)
		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
				USB_PORT_STAT_C_ENABLE);
#endif

	/* Try to resuscitate an existing device */
	udev = hub->ports[port1 - 1]->child;
	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
			udev->state != USB_STATE_NOTATTACHED) {
		usb_lock_device(udev);
		if (portstatus & USB_PORT_STAT_ENABLE) {
			status = 0;		/* Nothing to do */

#ifdef CONFIG_PM_RUNTIME
		} else if (udev->state == USB_STATE_SUSPENDED &&
				udev->persist_enabled) {
			/* For a suspended device, treat this as a
			 * remote wakeup event.
			 */
			status = usb_remote_wakeup(udev);
#endif

		} else {
			status = -ENODEV;	/* Don't resuscitate */
		}
		usb_unlock_device(udev);

		if (status == 0) {
			clear_bit(port1, hub->change_bits);
			return;
		}
	}

	/* Disconnect any existing devices under this port */
	if (udev) {
		if (hcd->phy && !hdev->parent &&
				!(portstatus & USB_PORT_STAT_CONNECTION))
			usb_phy_notify_disconnect(hcd->phy, udev->speed);
		usb_disconnect(&hub->ports[port1 - 1]->child);
	}
	clear_bit(port1, hub->change_bits);

	/* We can forget about a "removed" device when there's a physical
	 * disconnect or the connect status changes.
	 */
	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
			(portchange & USB_PORT_STAT_C_CONNECTION))
		clear_bit(port1, hub->removed_bits);

	if (portchange & (USB_PORT_STAT_C_CONNECTION |
				USB_PORT_STAT_C_ENABLE)) {
		status = hub_port_debounce_be_stable(hub, port1);
		if (status < 0) {
			if (status != -ENODEV && printk_ratelimit())
				dev_err(hub_dev, "connect-debounce failed, "
						"port %d disabled\n", port1);
			portstatus &= ~USB_PORT_STAT_CONNECTION;
		} else {
			portstatus = status;
		}
	}

	/* Return now if debouncing failed or nothing is connected or
	 * the device was "removed".
	 */
	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
			test_bit(port1, hub->removed_bits)) {

		/* maybe switch power back on (e.g. root hub was reset) */
		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
				&& !port_is_power_on(hub, portstatus))
			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);

		if (portstatus & USB_PORT_STAT_ENABLE)
  			goto done;
		return;
	}
	if (hub_is_superspeed(hub->hdev))
		unit_load = 150;
	else
		unit_load = 100;

	status = 0;
	for (i = 0; i < SET_CONFIG_TRIES; i++) {

		/* reallocate for each attempt, since references
		 * to the previous one can escape in various ways
		 */
		udev = usb_alloc_dev(hdev, hdev->bus, port1);
		if (!udev) {
			dev_err (hub_dev,
				"couldn't allocate port %d usb_device\n",
				port1);
			goto done;
		}

		usb_set_device_state(udev, USB_STATE_POWERED);
 		udev->bus_mA = hub->mA_per_port;
		udev->level = hdev->level + 1;
		udev->wusb = hub_is_wusb(hub);

		/* Only USB 3.0 devices are connected to SuperSpeed hubs. */
		if (hub_is_superspeed(hub->hdev))
			udev->speed = USB_SPEED_SUPER;
		else
			udev->speed = USB_SPEED_UNKNOWN;

		choose_devnum(udev);
		if (udev->devnum <= 0) {
			status = -ENOTCONN;	/* Don't retry */
			goto loop;
		}

		/* reset (non-USB 3.0 devices) and get descriptor */
		status = hub_port_init(hub, udev, port1, i);
		if (status < 0)
			goto loop;

		if (udev->quirks & USB_QUIRK_DELAY_INIT)
			msleep(1000);

		/* consecutive bus-powered hubs aren't reliable; they can
		 * violate the voltage drop budget.  if the new child has
		 * a "powered" LED, users should notice we didn't enable it
		 * (without reading syslog), even without per-port LEDs
		 * on the parent.
		 */
		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
				&& udev->bus_mA <= unit_load) {
			u16	devstat;

			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
					&devstat);
			if (status < 2) {
				dev_dbg(&udev->dev, "get status %d ?\n", status);
				goto loop_disable;
			}
			le16_to_cpus(&devstat);
			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
				dev_err(&udev->dev,
					"can't connect bus-powered hub "
					"to this port\n");
				if (hub->has_indicators) {
					hub->indicator[port1-1] =
						INDICATOR_AMBER_BLINK;
					schedule_delayed_work (&hub->leds, 0);
				}
				status = -ENOTCONN;	/* Don't retry */
				goto loop_disable;
			}
		}
 
		/* check for devices running slower than they could */
		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
				&& udev->speed == USB_SPEED_FULL
				&& highspeed_hubs != 0)
			check_highspeed (hub, udev, port1);

		/* Store the parent's children[] pointer.  At this point
		 * udev becomes globally accessible, although presumably
		 * no one will look at it until hdev is unlocked.
		 */
		status = 0;

		/* We mustn't add new devices if the parent hub has
		 * been disconnected; we would race with the
		 * recursively_mark_NOTATTACHED() routine.
		 */
		spin_lock_irq(&device_state_lock);
		if (hdev->state == USB_STATE_NOTATTACHED)
			status = -ENOTCONN;
		else
			hub->ports[port1 - 1]->child = udev;
		spin_unlock_irq(&device_state_lock);

		/* Run it through the hoops (find a driver, etc) */
		if (!status) {
			status = usb_new_device(udev);
			if (status) {
				spin_lock_irq(&device_state_lock);
				hub->ports[port1 - 1]->child = NULL;
				spin_unlock_irq(&device_state_lock);
			}
		}

		if (status)
			goto loop_disable;

		status = hub_power_remaining(hub);
		if (status)
			dev_dbg(hub_dev, "%dmA power budget left\n", status);

		return;

loop_disable:
		hub_port_disable(hub, port1, 1);
loop:
		usb_ep0_reinit(udev);
		release_devnum(udev);
		hub_free_dev(udev);
		usb_put_dev(udev);
		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
			break;
	}
	if (hub->hdev->parent ||
			!hcd->driver->port_handed_over ||
			!(hcd->driver->port_handed_over)(hcd, port1)) {
		if (status != -ENOTCONN && status != -ENODEV)
			dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
					port1);
	}
 
done:
	hub_port_disable(hub, port1, 1);
	if (hcd->driver->relinquish_port && !hub->hdev->parent)
		hcd->driver->relinquish_port(hcd, port1);
}

/* Returns 1 if there was a remote wakeup and a connect status change. */
static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
		u16 portstatus, u16 portchange)
{
	struct usb_device *hdev;
	struct usb_device *udev;
	int connect_change = 0;
	int ret;

	hdev = hub->hdev;
	udev = hub->ports[port - 1]->child;
	if (!hub_is_superspeed(hdev)) {
		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
			return 0;
		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
	} else {
		if (!udev || udev->state != USB_STATE_SUSPENDED ||
				 (portstatus & USB_PORT_STAT_LINK_STATE) !=
				 USB_SS_PORT_LS_U0)
			return 0;
	}

	if (udev) {
		/* TRSMRCY = 10 msec */
		msleep(10);

		usb_lock_device(udev);
		ret = usb_remote_wakeup(udev);
		usb_unlock_device(udev);
		if (ret < 0)
			connect_change = 1;
	} else {
		ret = -ENODEV;
		hub_port_disable(hub, port, 1);
	}
	dev_dbg(hub->intfdev, "resume on port %d, status %d\n",
			port, ret);
	return connect_change;
}

static void hub_events(void)
{
	struct list_head *tmp;
	struct usb_device *hdev;
	struct usb_interface *intf;
	struct usb_hub *hub;
	struct device *hub_dev;
	u16 hubstatus;
	u16 hubchange;
	u16 portstatus;
	u16 portchange;
	int i, ret;
	int connect_change, wakeup_change;

	/*
	 *  We restart the list every time to avoid a deadlock with
	 * deleting hubs downstream from this one. This should be
	 * safe since we delete the hub from the event list.
	 * Not the most efficient, but avoids deadlocks.
	 */
	while (1) {

		/* Grab the first entry at the beginning of the list */
		spin_lock_irq(&hub_event_lock);
		if (list_empty(&hub_event_list)) {
			spin_unlock_irq(&hub_event_lock);
			break;
		}

		tmp = hub_event_list.next;
		list_del_init(tmp);

		hub = list_entry(tmp, struct usb_hub, event_list);
		kref_get(&hub->kref);

		/* make sure hdev is not freed before accessing it */
		if (hub->disconnected) {
			spin_unlock_irq(&hub_event_lock);
			goto hub_disconnected;
		} else {
			hdev = hub->hdev;
			usb_get_dev(hdev);
		}
		spin_unlock_irq(&hub_event_lock);

		hub_dev = hub->intfdev;
		intf = to_usb_interface(hub_dev);
		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
				hdev->state, hub->descriptor
					? hub->descriptor->bNbrPorts
					: 0,
				/* NOTE: expects max 15 ports... */
				(u16) hub->change_bits[0],
				(u16) hub->event_bits[0]);

		/* Lock the device, then check to see if we were
		 * disconnected while waiting for the lock to succeed. */
		usb_lock_device(hdev);
		if (unlikely(hub->disconnected))
			goto loop_disconnected;

		/* If the hub has died, clean up after it */
		if (hdev->state == USB_STATE_NOTATTACHED) {
			hub->error = -ENODEV;
			hub_quiesce(hub, HUB_DISCONNECT);
			goto loop;
		}

		/* Autoresume */
		ret = usb_autopm_get_interface(intf);
		if (ret) {
			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
			goto loop;
		}

		/* If this is an inactive hub, do nothing */
		if (hub->quiescing)
			goto loop_autopm;

		if (hub->error) {
			dev_dbg (hub_dev, "resetting for error %d\n",
				hub->error);

			ret = usb_reset_device(hdev);
			if (ret) {
				dev_dbg (hub_dev,
					"error resetting hub: %d\n", ret);
				goto loop_autopm;
			}

			hub->nerrors = 0;
			hub->error = 0;
		}

		/* deal with port status changes */
		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
			if (test_bit(i, hub->busy_bits))
				continue;
			connect_change = test_bit(i, hub->change_bits);
			wakeup_change = test_and_clear_bit(i, hub->wakeup_bits);
			if (!test_and_clear_bit(i, hub->event_bits) &&
					!connect_change && !wakeup_change)
				continue;

			ret = hub_port_status(hub, i,
					&portstatus, &portchange);
			if (ret < 0)
				continue;

			if (portchange & USB_PORT_STAT_C_CONNECTION) {
				usb_clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_CONNECTION);
				connect_change = 1;
			}

			if (portchange & USB_PORT_STAT_C_ENABLE) {
				if (!connect_change)
					dev_dbg (hub_dev,
						"port %d enable change, "
						"status %08x\n",
						i, portstatus);
				usb_clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_ENABLE);

				/*
				 * EM interference sometimes causes badly
				 * shielded USB devices to be shutdown by
				 * the hub, this hack enables them again.
				 * Works at least with mouse driver. 
				 */
				if (!(portstatus & USB_PORT_STAT_ENABLE)
				    && !connect_change
				    && hub->ports[i - 1]->child) {
					dev_err (hub_dev,
					    "port %i "
					    "disabled by hub (EMI?), "
					    "re-enabling...\n",
						i);
					connect_change = 1;
				}
			}

			if (hub_handle_remote_wakeup(hub, i,
						portstatus, portchange))
				connect_change = 1;

			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
				u16 status = 0;
				u16 unused;

				dev_dbg(hub_dev, "over-current change on port "
					"%d\n", i);
				usb_clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_OVER_CURRENT);
				msleep(100);	/* Cool down */
				hub_power_on(hub, true);
				hub_port_status(hub, i, &status, &unused);
				if (status & USB_PORT_STAT_OVERCURRENT)
					dev_err(hub_dev, "over-current "
						"condition on port %d\n", i);
			}

			if (portchange & USB_PORT_STAT_C_RESET) {
				dev_dbg (hub_dev,
					"reset change on port %d\n",
					i);
				usb_clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_RESET);
			}
			if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
					hub_is_superspeed(hub->hdev)) {
				dev_dbg(hub_dev,
					"warm reset change on port %d\n",
					i);
				usb_clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_BH_PORT_RESET);
			}
			if (portchange & USB_PORT_STAT_C_LINK_STATE) {
				usb_clear_port_feature(hub->hdev, i,
						USB_PORT_FEAT_C_PORT_LINK_STATE);
			}
			if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
				dev_warn(hub_dev,
					"config error on port %d\n",
					i);
				usb_clear_port_feature(hub->hdev, i,
						USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
			}

			/* Warm reset a USB3 protocol port if it's in
			 * SS.Inactive state.
			 */
			if (hub_port_warm_reset_required(hub, portstatus)) {
				int status;
				struct usb_device *udev =
					hub->ports[i - 1]->child;

				dev_dbg(hub_dev, "warm reset port %d\n", i);
				if (!udev ||
				    !(portstatus & USB_PORT_STAT_CONNECTION) ||
				    udev->state == USB_STATE_NOTATTACHED) {
					status = hub_port_reset(hub, i,
							NULL, HUB_BH_RESET_TIME,
							true);
					if (status < 0)
						hub_port_disable(hub, i, 1);
				} else {
					usb_lock_device(udev);
					status = usb_reset_device(udev);
					usb_unlock_device(udev);
					connect_change = 0;
				}
			}

			if (connect_change)
				hub_port_connect_change(hub, i,
						portstatus, portchange);
		} /* end for i */

		/* deal with hub status changes */
		if (test_and_clear_bit(0, hub->event_bits) == 0)
			;	/* do nothing */
		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
			dev_err (hub_dev, "get_hub_status failed\n");
		else {
			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
				dev_dbg (hub_dev, "power change\n");
				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
				if (hubstatus & HUB_STATUS_LOCAL_POWER)
					/* FIXME: Is this always true? */
					hub->limited_power = 1;
				else
					hub->limited_power = 0;
			}
			if (hubchange & HUB_CHANGE_OVERCURRENT) {
				u16 status = 0;
				u16 unused;

				dev_dbg(hub_dev, "over-current change\n");
				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
				msleep(500);	/* Cool down */
                        	hub_power_on(hub, true);
				hub_hub_status(hub, &status, &unused);
				if (status & HUB_STATUS_OVERCURRENT)
					dev_err(hub_dev, "over-current "
						"condition\n");
			}
		}

 loop_autopm:
		/* Balance the usb_autopm_get_interface() above */
		usb_autopm_put_interface_no_suspend(intf);
 loop:
		/* Balance the usb_autopm_get_interface_no_resume() in
		 * kick_khubd() and allow autosuspend.
		 */
		usb_autopm_put_interface(intf);
 loop_disconnected:
		usb_unlock_device(hdev);
		usb_put_dev(hdev);
 hub_disconnected:
		kref_put(&hub->kref, hub_release);

        } /* end while (1) */
}

static int hub_thread(void *__unused)
{
	/* khubd needs to be freezable to avoid intefering with USB-PERSIST
	 * port handover.  Otherwise it might see that a full-speed device
	 * was gone before the EHCI controller had handed its port over to
	 * the companion full-speed controller.
	 */
	set_freezable();

	do {
		hub_events();
		wait_event_freezable(khubd_wait,
				!list_empty(&hub_event_list) ||
				kthread_should_stop());
	} while (!kthread_should_stop() || !list_empty(&hub_event_list));

	pr_debug("%s: khubd exiting\n", usbcore_name);
	return 0;
}

static const struct usb_device_id hub_id_table[] = {
    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
	           | USB_DEVICE_ID_MATCH_INT_CLASS,
      .idVendor = USB_VENDOR_GENESYS_LOGIC,
      .bInterfaceClass = USB_CLASS_HUB,
      .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
    { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
      .bDeviceClass = USB_CLASS_HUB},
    { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
      .bInterfaceClass = USB_CLASS_HUB},
    { }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, hub_id_table);

static struct usb_driver hub_driver = {
	.name =		"hub",
	.probe =	hub_probe,
	.disconnect =	hub_disconnect,
	.suspend =	hub_suspend,
	.resume =	hub_resume,
	.reset_resume =	hub_reset_resume,
	.pre_reset =	hub_pre_reset,
	.post_reset =	hub_post_reset,
	.unlocked_ioctl = hub_ioctl,
	.id_table =	hub_id_table,
	.supports_autosuspend =	1,
};

int usb_hub_init(void)
{
	if (usb_register(&hub_driver) < 0) {
		printk(KERN_ERR "%s: can't register hub driver\n",
			usbcore_name);
		return -1;
	}

	khubd_task = kthread_run(hub_thread, NULL, "khubd");
	if (!IS_ERR(khubd_task))
		return 0;

	/* Fall through if kernel_thread failed */
	usb_deregister(&hub_driver);
	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);

	return -1;
}

void usb_hub_cleanup(void)
{
	kthread_stop(khubd_task);

	/*
	 * Hub resources are freed for us by usb_deregister. It calls
	 * usb_driver_purge on every device which in turn calls that
	 * devices disconnect function if it is using this driver.
	 * The hub_disconnect function takes care of releasing the
	 * individual hub resources. -greg
	 */
	usb_deregister(&hub_driver);
} /* usb_hub_cleanup() */

static int descriptors_changed(struct usb_device *udev,
		struct usb_device_descriptor *old_device_descriptor)
{
	int		changed = 0;
	unsigned	index;
	unsigned	serial_len = 0;
	unsigned	len;
	unsigned	old_length;
	int		length;
	char		*buf;

	if (memcmp(&udev->descriptor, old_device_descriptor,
			sizeof(*old_device_descriptor)) != 0)
		return 1;

	/* Since the idVendor, idProduct, and bcdDevice values in the
	 * device descriptor haven't changed, we will assume the
	 * Manufacturer and Product strings haven't changed either.
	 * But the SerialNumber string could be different (e.g., a
	 * different flash card of the same brand).
	 */
	if (udev->serial)
		serial_len = strlen(udev->serial) + 1;

	len = serial_len;
	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
		len = max(len, old_length);
	}

	buf = kmalloc(len, GFP_NOIO);
	if (buf == NULL) {
		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
		/* assume the worst */
		return 1;
	}
	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
				old_length);
		if (length != old_length) {
			dev_dbg(&udev->dev, "config index %d, error %d\n",
					index, length);
			changed = 1;
			break;
		}
		if (memcmp (buf, udev->rawdescriptors[index], old_length)
				!= 0) {
			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
				index,
				((struct usb_config_descriptor *) buf)->
					bConfigurationValue);
			changed = 1;
			break;
		}
	}

	if (!changed && serial_len) {
		length = usb_string(udev, udev->descriptor.iSerialNumber,
				buf, serial_len);
		if (length + 1 != serial_len) {
			dev_dbg(&udev->dev, "serial string error %d\n",
					length);
			changed = 1;
		} else if (memcmp(buf, udev->serial, length) != 0) {
			dev_dbg(&udev->dev, "serial string changed\n");
			changed = 1;
		}
	}

	kfree(buf);
	return changed;
}

/**
 * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
 *
 * WARNING - don't use this routine to reset a composite device
 * (one with multiple interfaces owned by separate drivers)!
 * Use usb_reset_device() instead.
 *
 * Do a port reset, reassign the device's address, and establish its
 * former operating configuration.  If the reset fails, or the device's
 * descriptors change from their values before the reset, or the original
 * configuration and altsettings cannot be restored, a flag will be set
 * telling khubd to pretend the device has been disconnected and then
 * re-connected.  All drivers will be unbound, and the device will be
 * re-enumerated and probed all over again.
 *
 * Returns 0 if the reset succeeded, -ENODEV if the device has been
 * flagged for logical disconnection, or some other negative error code
 * if the reset wasn't even attempted.
 *
 * The caller must own the device lock.  For example, it's safe to use
 * this from a driver probe() routine after downloading new firmware.
 * For calls that might not occur during probe(), drivers should lock
 * the device using usb_lock_device_for_reset().
 *
 * Locking exception: This routine may also be called from within an
 * autoresume handler.  Such usage won't conflict with other tasks
 * holding the device lock because these tasks should always call
 * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
 */
static int usb_reset_and_verify_device(struct usb_device *udev)
{
	struct usb_device		*parent_hdev = udev->parent;
	struct usb_hub			*parent_hub;
	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
	struct usb_device_descriptor	descriptor = udev->descriptor;
	int 				i, ret = 0;
	int				port1 = udev->portnum;

	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
				udev->state);
		return -EINVAL;
	}

	if (!parent_hdev) {
		/* this requires hcd-specific logic; see ohci_restart() */
		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
		return -EISDIR;
	}
	parent_hub = usb_hub_to_struct_hub(parent_hdev);

	/* Disable LPM and LTM while we reset the device and reinstall the alt
	 * settings.  Device-initiated LPM settings, and system exit latency
	 * settings are cleared when the device is reset, so we have to set
	 * them up again.
	 */
	ret = usb_unlocked_disable_lpm(udev);
	if (ret) {
		dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
		goto re_enumerate;
	}
	ret = usb_disable_ltm(udev);
	if (ret) {
		dev_err(&udev->dev, "%s Failed to disable LTM\n.",
				__func__);
		goto re_enumerate;
	}

	set_bit(port1, parent_hub->busy_bits);
	for (i = 0; i < SET_CONFIG_TRIES; ++i) {

		/* ep0 maxpacket size may change; let the HCD know about it.
		 * Other endpoints will be handled by re-enumeration. */
		usb_ep0_reinit(udev);
		ret = hub_port_init(parent_hub, udev, port1, i);
		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
			break;
	}
	clear_bit(port1, parent_hub->busy_bits);

	if (ret < 0)
		goto re_enumerate;
 
	/* Device might have changed firmware (DFU or similar) */
	if (descriptors_changed(udev, &descriptor)) {
		dev_info(&udev->dev, "device firmware changed\n");
		udev->descriptor = descriptor;	/* for disconnect() calls */
		goto re_enumerate;
  	}

	/* Restore the device's previous configuration */
	if (!udev->actconfig)
		goto done;

	mutex_lock(hcd->bandwidth_mutex);
	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
	if (ret < 0) {
		dev_warn(&udev->dev,
				"Busted HC?  Not enough HCD resources for "
				"old configuration.\n");
		mutex_unlock(hcd->bandwidth_mutex);
		goto re_enumerate;
	}
	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_SET_CONFIGURATION, 0,
			udev->actconfig->desc.bConfigurationValue, 0,
			NULL, 0, USB_CTRL_SET_TIMEOUT);
	if (ret < 0) {
		dev_err(&udev->dev,
			"can't restore configuration #%d (error=%d)\n",
			udev->actconfig->desc.bConfigurationValue, ret);
		mutex_unlock(hcd->bandwidth_mutex);
		goto re_enumerate;
  	}
	mutex_unlock(hcd->bandwidth_mutex);
	usb_set_device_state(udev, USB_STATE_CONFIGURED);

	/* Put interfaces back into the same altsettings as before.
	 * Don't bother to send the Set-Interface request for interfaces
	 * that were already in altsetting 0; besides being unnecessary,
	 * many devices can't handle it.  Instead just reset the host-side
	 * endpoint state.
	 */
	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
		struct usb_host_config *config = udev->actconfig;
		struct usb_interface *intf = config->interface[i];
		struct usb_interface_descriptor *desc;

		desc = &intf->cur_altsetting->desc;
		if (desc->bAlternateSetting == 0) {
			usb_disable_interface(udev, intf, true);
			usb_enable_interface(udev, intf, true);
			ret = 0;
		} else {
			/* Let the bandwidth allocation function know that this
			 * device has been reset, and it will have to use
			 * alternate setting 0 as the current alternate setting.
			 */
			intf->resetting_device = 1;
			ret = usb_set_interface(udev, desc->bInterfaceNumber,
					desc->bAlternateSetting);
			intf->resetting_device = 0;
		}
		if (ret < 0) {
			dev_err(&udev->dev, "failed to restore interface %d "
				"altsetting %d (error=%d)\n",
				desc->bInterfaceNumber,
				desc->bAlternateSetting,
				ret);
			goto re_enumerate;
		}
	}

done:
	/* Now that the alt settings are re-installed, enable LTM and LPM. */
	usb_unlocked_enable_lpm(udev);
	usb_enable_ltm(udev);
	return 0;
 
re_enumerate:
	/* LPM state doesn't matter when we're about to destroy the device. */
	hub_port_logical_disconnect(parent_hub, port1);
	return -ENODEV;
}

/**
 * usb_reset_device - warn interface drivers and perform a USB port reset
 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
 *
 * Warns all drivers bound to registered interfaces (using their pre_reset
 * method), performs the port reset, and then lets the drivers know that
 * the reset is over (using their post_reset method).
 *
 * Return value is the same as for usb_reset_and_verify_device().
 *
 * The caller must own the device lock.  For example, it's safe to use
 * this from a driver probe() routine after downloading new firmware.
 * For calls that might not occur during probe(), drivers should lock
 * the device using usb_lock_device_for_reset().
 *
 * If an interface is currently being probed or disconnected, we assume
 * its driver knows how to handle resets.  For all other interfaces,
 * if the driver doesn't have pre_reset and post_reset methods then
 * we attempt to unbind it and rebind afterward.
 */
int usb_reset_device(struct usb_device *udev)
{
	int ret;
	int i;
	unsigned int noio_flag;
	struct usb_host_config *config = udev->actconfig;

	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
				udev->state);
		return -EINVAL;
	}

	/*
	 * Don't allocate memory with GFP_KERNEL in current
	 * context to avoid possible deadlock if usb mass
	 * storage interface or usbnet interface(iSCSI case)
	 * is included in current configuration. The easist
	 * approach is to do it for every device reset,
	 * because the device 'memalloc_noio' flag may have
	 * not been set before reseting the usb device.
	 */
	noio_flag = memalloc_noio_save();

	/* Prevent autosuspend during the reset */
	usb_autoresume_device(udev);

	if (config) {
		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
			struct usb_interface *cintf = config->interface[i];
			struct usb_driver *drv;
			int unbind = 0;

			if (cintf->dev.driver) {
				drv = to_usb_driver(cintf->dev.driver);
				if (drv->pre_reset && drv->post_reset)
					unbind = (drv->pre_reset)(cintf);
				else if (cintf->condition ==
						USB_INTERFACE_BOUND)
					unbind = 1;
				if (unbind)
					usb_forced_unbind_intf(cintf);
			}
		}
	}

	ret = usb_reset_and_verify_device(udev);

	if (config) {
		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
			struct usb_interface *cintf = config->interface[i];
			struct usb_driver *drv;
			int rebind = cintf->needs_binding;

			if (!rebind && cintf->dev.driver) {
				drv = to_usb_driver(cintf->dev.driver);
				if (drv->post_reset)
					rebind = (drv->post_reset)(cintf);
				else if (cintf->condition ==
						USB_INTERFACE_BOUND)
					rebind = 1;
				if (rebind)
					cintf->needs_binding = 1;
			}
		}
		usb_unbind_and_rebind_marked_interfaces(udev);
	}

	usb_autosuspend_device(udev);
	memalloc_noio_restore(noio_flag);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_reset_device);


/**
 * usb_queue_reset_device - Reset a USB device from an atomic context
 * @iface: USB interface belonging to the device to reset
 *
 * This function can be used to reset a USB device from an atomic
 * context, where usb_reset_device() won't work (as it blocks).
 *
 * Doing a reset via this method is functionally equivalent to calling
 * usb_reset_device(), except for the fact that it is delayed to a
 * workqueue. This means that any drivers bound to other interfaces
 * might be unbound, as well as users from usbfs in user space.
 *
 * Corner cases:
 *
 * - Scheduling two resets at the same time from two different drivers
 *   attached to two different interfaces of the same device is
 *   possible; depending on how the driver attached to each interface
 *   handles ->pre_reset(), the second reset might happen or not.
 *
 * - If a driver is unbound and it had a pending reset, the reset will
 *   be cancelled.
 *
 * - This function can be called during .probe() or .disconnect()
 *   times. On return from .disconnect(), any pending resets will be
 *   cancelled.
 *
 * There is no no need to lock/unlock the @reset_ws as schedule_work()
 * does its own.
 *
 * NOTE: We don't do any reference count tracking because it is not
 *     needed. The lifecycle of the work_struct is tied to the
 *     usb_interface. Before destroying the interface we cancel the
 *     work_struct, so the fact that work_struct is queued and or
 *     running means the interface (and thus, the device) exist and
 *     are referenced.
 */
void usb_queue_reset_device(struct usb_interface *iface)
{
	schedule_work(&iface->reset_ws);
}
EXPORT_SYMBOL_GPL(usb_queue_reset_device);

/**
 * usb_hub_find_child - Get the pointer of child device
 * attached to the port which is specified by @port1.
 * @hdev: USB device belonging to the usb hub
 * @port1: port num to indicate which port the child device
 *	is attached to.
 *
 * USB drivers call this function to get hub's child device
 * pointer.
 *
 * Return NULL if input param is invalid and
 * child's usb_device pointer if non-NULL.
 */
struct usb_device *usb_hub_find_child(struct usb_device *hdev,
		int port1)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (port1 < 1 || port1 > hdev->maxchild)
		return NULL;
	return hub->ports[port1 - 1]->child;
}
EXPORT_SYMBOL_GPL(usb_hub_find_child);

/**
 * usb_set_hub_port_connect_type - set hub port connect type.
 * @hdev: USB device belonging to the usb hub
 * @port1: port num of the port
 * @type: connect type of the port
 */
void usb_set_hub_port_connect_type(struct usb_device *hdev, int port1,
	enum usb_port_connect_type type)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (hub)
		hub->ports[port1 - 1]->connect_type = type;
}

/**
 * usb_get_hub_port_connect_type - Get the port's connect type
 * @hdev: USB device belonging to the usb hub
 * @port1: port num of the port
 *
 * Return connect type of the port and if input params are
 * invalid, return USB_PORT_CONNECT_TYPE_UNKNOWN.
 */
enum usb_port_connect_type
usb_get_hub_port_connect_type(struct usb_device *hdev, int port1)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (!hub)
		return USB_PORT_CONNECT_TYPE_UNKNOWN;

	return hub->ports[port1 - 1]->connect_type;
}

void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
		struct usb_hub_descriptor *desc)
{
	enum usb_port_connect_type connect_type;
	int i;

	if (!hub_is_superspeed(hdev)) {
		for (i = 1; i <= hdev->maxchild; i++) {
			connect_type = usb_get_hub_port_connect_type(hdev, i);

			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
				u8 mask = 1 << (i%8);

				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
					dev_dbg(&hdev->dev, "usb port%d's DeviceRemovable is changed to 1 according to platform information.\n",
						i);
					desc->u.hs.DeviceRemovable[i/8]	|= mask;
				}
			}
		}
	} else {
		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);

		for (i = 1; i <= hdev->maxchild; i++) {
			connect_type = usb_get_hub_port_connect_type(hdev, i);

			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
				u16 mask = 1 << i;

				if (!(port_removable & mask)) {
					dev_dbg(&hdev->dev, "usb port%d's DeviceRemovable is changed to 1 according to platform information.\n",
						i);
					port_removable |= mask;
				}
			}
		}

		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
	}
}

#ifdef CONFIG_ACPI
/**
 * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
 * @hdev: USB device belonging to the usb hub
 * @port1: port num of the port
 *
 * Return port's acpi handle if successful, NULL if params are
 * invaild.
 */
acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
	int port1)
{
	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);

	if (!hub)
		return NULL;

	return DEVICE_ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
}
#endif

[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux