On 2013/1/22 5:30, Greg KH wrote:
On Mon, Jan 21, 2013 at 10:18:04PM +0800, Lan Tianyu wrote:
This patch is to add usb port auto power off mechanism.
When usb device is suspending, usb core will suspend usb port and
usb port runtime pm callback will clear PORT_POWER feature to
power off port if all conditions were met. These conditions are
remote wakeup disable, pm qos NO_POWER_OFF flag clear and persist
enable. When it resumes, power on port again. Add did_runtime_put
in the struct usb_port in order to call pm_runtime_get/put(portdev)
paired during suspending and resuming.
I don't understand what did_runtime_put is supposed to mean. Care to
explain this better?
Ok.
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
drivers/usb/core/hub.c | 67 ++++++++++++++++++++++++++++++++++++++++-------
drivers/usb/core/hub.h | 9 +++++++
drivers/usb/core/port.c | 40 ++++++++++++++++++++++++++--
3 files changed, 105 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 8c1f9a5..786db99 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -26,6 +26,7 @@
#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>
@@ -108,7 +109,7 @@ MODULE_PARM_DESC(use_both_schemes,
DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
-#define HUB_DEBOUNCE_TIMEOUT 1500
+#define HUB_DEBOUNCE_TIMEOUT 2000
Why did you increase this timeout? You don't mention that above in the
changelog entry.
I will add this into change log.
#define HUB_DEBOUNCE_STEP 25
#define HUB_DEBOUNCE_STABLE 100
@@ -127,7 +128,7 @@ static inline char *portspeed(struct usb_hub *hub, int portstatus)
}
/* Note that hdev or one of its children must be locked! */
-static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
+struct usb_hub *hdev_to_hub(struct usb_device *hdev)
This needs a better name now that this is a global function. No one
knows what a "hdev" is.
Actually the routine will only be used in the driver/usb/core/(hub.c,
port.c). Port also should be the part of hub, right? Moving port related
code to port.c is to make code more clear. I am not sure whether we
should rename it.
If we renamed it, how about "usb_hub_to_struct_hub"? \
Should we do rename operation in a separate patch since hdev_to_hub() is
called many places in the hub.c?
{
if (!hdev || !hdev->actconfig || !hdev->maxchild)
return NULL;
@@ -393,7 +394,7 @@ static int clear_hub_feature(struct usb_device *hdev, int feature)
/*
* USB 2.0 spec Section 11.24.2.2
*/
-static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
+int clear_port_feature(struct usb_device *hdev, int port1, int feature)
This is now a global function, please put usb_ infront of it.
Same above?
{
return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
@@ -718,11 +719,16 @@ int usb_hub_set_port_power(struct usb_device *hdev, int port1,
bool set)
{
int ret;
+ struct usb_hub *hub = hdev_to_hub(hdev);
+ struct usb_port *port_dev = hub->ports[port1 - 1];
if (set)
ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
else
ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
+
+ if (!ret)
+ port_dev->power_is_on = set;
return ret;
}
@@ -802,7 +808,11 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
dev_dbg(hub->intfdev, "trying to enable port power on "
"non-switchable hub\n");
for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
- set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
+ if (hub->ports[port1 - 1]->power_is_on)
+ set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
+ else
+ 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);
@@ -1134,10 +1144,16 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
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
- set_bit(port1, hub->change_bits);
+ /* 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 */
@@ -2012,7 +2028,10 @@ void usb_disconnect(struct usb_device **pdev)
sysfs_remove_link(&udev->dev.kobj, "port");
sysfs_remove_link(&port_dev->dev.kobj, "device");
- pm_runtime_put(&port_dev->dev);
+ 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);
@@ -2844,6 +2863,8 @@ EXPORT_SYMBOL_GPL(usb_enable_ltm);
int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
+ struct usb_port *port_dev = hub->ports[udev->portnum - 1];
+ enum pm_qos_flags_status pm_qos_stat;
int port1 = udev->portnum;
int status;
@@ -2936,6 +2957,21 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
udev->port_is_suspended = 1;
msleep(10);
}
+
+ /*
+ * Check whether current status meets the requirement of
+ * usb port power off mechanism
+ */
+ pm_qos_stat = dev_pm_qos_flags(&port_dev->dev,
+ PM_QOS_FLAG_NO_POWER_OFF);
+ if (!udev->do_remote_wakeup
+ && pm_qos_stat != PM_QOS_FLAGS_ALL
+ && udev->persist_enabled
+ && !status) {
+ pm_runtime_put_sync(&port_dev->dev);
+ port_dev->did_runtime_put = true;
+ }
+
usb_mark_last_busy(hub->hdev);
return status;
}
@@ -3062,10 +3098,21 @@ static int finish_port_resume(struct usb_device *udev)
int usb_port_resume(struct usb_device *udev, pm_message_t msg)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
+ struct usb_port *port_dev = hub->ports[udev->portnum - 1];
int port1 = udev->portnum;
int status;
u16 portchange, portstatus;
+ 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))
@@ -3744,7 +3791,7 @@ EXPORT_SYMBOL_GPL(usb_enable_ltm);
* every 25ms for transient disconnects. When the port status has been
* unchanged for 100ms it returns the port status.
*/
-static int hub_port_debounce(struct usb_hub *hub, int port1)
+int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
I hate boolean flags in functions that do different things depending on
the value. Can you just make two different functions here, and have
them call this private one with the proper flag set?
Sorry. I am not very sure I understand correctly.
Do you mean to create two wraps which call hub_port_debounce()?
Just like
hub_port_debounce_be_counted()
{
hub_port_debounce(...,..., true);
}
hub_port_debounce_be_counted()
{
hub_port_debounce(...,..., false);
}
Otherwise, when
you see this function called, you have to go look up what the
"true/false" means and it wastes time and makes it very easy to get
wrong in the future.
{
int ret;
int total_time, stable_time = 0;
@@ -3758,7 +3805,9 @@ static int hub_port_debounce(struct usb_hub *hub, int port1)
if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
(portstatus & USB_PORT_STAT_CONNECTION) == connection) {
- stable_time += HUB_DEBOUNCE_STEP;
+ if (!must_be_connected || (connection
+ == USB_PORT_STAT_CONNECTION))
Please do:
if (!must_be_connected ||
(connection == USB_PORT_STAT_CONNECTION))
instead, that makes it much more readable.
Oh. I originally do the same thing. But there is following code which
requires this line to be more indention. This will cause this line over
80 characters. So I had to break this line.
I finally find that if I just do following, it also can work.
if (!must_be_connected || connection)
stable_time += HUB_DEBOUNCE_STEP;
Does this make sense? Since connection only will be assigned to the
result of "portstatus & USB_PORT_STAT_CONNECTION".
thanks,
greg k-h
+ stable_time += HUB_DEBOUNCE_STEP;
if (stable_time >= HUB_DEBOUNCE_STABLE)
break;
} else {
@@ -4279,7 +4328,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
if (portchange & (USB_PORT_STAT_C_CONNECTION |
USB_PORT_STAT_C_ENABLE)) {
- status = hub_port_debounce(hub, port1);
+ status = hub_port_debounce(hub, port1, false);
if (status < 0) {
if (printk_ratelimit())
dev_err(hub_dev, "connect-debounce failed, "
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 8ea6bc8..ccd4795 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -80,6 +80,8 @@ struct usb_hub {
* @port_owner: port's owner
* @connect_type: port's connect type
* @portnum: port index num based one
+ * @power_is_on: port's power state
+ * @did_runtime_put: port has done pm_runtime_put().
*/
struct usb_port {
struct usb_device *child;
@@ -87,6 +89,8 @@ struct usb_port {
struct dev_state *port_owner;
enum usb_port_connect_type connect_type;
u8 portnum;
+ unsigned power_is_on:1;
+ unsigned did_runtime_put:1;
};
#define to_usb_port(_dev) \
@@ -98,4 +102,9 @@ extern void usb_hub_remove_port_device(struct usb_hub *hub,
int port1);
extern int usb_hub_set_port_power(struct usb_device *hdev,
int port1, bool set);
+extern struct usb_hub *hdev_to_hub(struct usb_device *hdev);
+extern int hub_port_debounce(struct usb_hub *hub, int port1,
+ bool must_be_connected);
+extern int clear_port_feature(struct usb_device *hdev,
+ int port1, int feature);
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index bd08f7e..dc1aaec 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -77,10 +77,36 @@ static int usb_port_runtime_resume(struct device *dev)
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
+ struct usb_hub *hub = hdev_to_hub(hdev);
+ int port1 = port_dev->portnum;
int retval;
+ if (!hub)
+ return -EINVAL;
+
usb_autopm_get_interface(intf);
- retval = usb_hub_set_port_power(hdev, port_dev->portnum, true);
+ set_bit(port1, hub->busy_bits);
+
+ retval = usb_hub_set_port_power(hdev, port1, true);
+ if (port_dev->child && !retval) {
+ /*
+ * Wait for usb hub port to be reconnected in order to make
+ * the resume procedure successful.
+ */
+ retval = hub_port_debounce(hub, port1, true);
+ if (retval < 0) {
+ dev_dbg(&port_dev->dev, "can't get reconnection after setting port power on, status %d\n",
+ retval);
+ goto out;
+ }
+ clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
+
+ /* Set return value to 0 if debounce successful */
+ retval = 0;
+ }
+
+out:
+ clear_bit(port1, hub->busy_bits);
usb_autopm_put_interface(intf);
return retval;
}
@@ -90,14 +116,23 @@ static int usb_port_runtime_suspend(struct device *dev)
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
+ struct usb_hub *hub = hdev_to_hub(hdev);
+ int port1 = port_dev->portnum;
int retval;
+ if (!hub)
+ return -EINVAL;
+
if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
== PM_QOS_FLAGS_ALL)
return -EAGAIN;
usb_autopm_get_interface(intf);
- retval = usb_hub_set_port_power(hdev, port_dev->portnum, false);
+ set_bit(port1, hub->busy_bits);
+ retval = usb_hub_set_port_power(hdev, port1, false);
+ clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
+ clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
+ clear_bit(port1, hub->busy_bits);
usb_autopm_put_interface(intf);
return retval;
}
@@ -130,6 +165,7 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
hub->ports[port1 - 1] = port_dev;
port_dev->portnum = port1;
+ port_dev->power_is_on = true;
port_dev->dev.parent = hub->intfdev;
port_dev->dev.groups = port_dev_group;
port_dev->dev.type = &usb_port_device_type;
--
1.7.9.5
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--
Best Regards
Tianyu Lan
linux kernel enabling team
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