On 15.5.20. 15:07, Greg KH wrote:
> On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
>> --- /dev/null
>> +++ b/drivers/usb/host/mausb/hcd.c
>> @@ -0,0 +1,120 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
>> + */
>> +#include "hcd.h"
>> +
>> +#include "utils.h"
>> +
>> +static int mausb_bus_match(struct device *dev, struct device_driver *drv);
>> +
>> +static const struct file_operations mausb_fops;
>> +
>> +static unsigned int major;
>> +static unsigned int minor = 1;
>> +static dev_t devt;
>> +static struct device *device;
>> +
>> +struct mausb_hcd *mhcd;
>> +static struct class *mausb_class;
>> +static struct bus_type mausb_bus_type = {
>> + .name = DEVICE_NAME,
>> + .match = mausb_bus_match,
>> +};
>
> A static bus type??? For a single driver?
>
>> +
>> +static struct device_driver mausb_driver = {
>> + .name = DEVICE_NAME,
>> + .bus = &mausb_bus_type,
>> + .owner = THIS_MODULE,
>> +};
>
> Wait, what??? A static "raw" struct device_driver? Why???
This was our initial driver setup that was "inherited" from some
in-tree drivers. We are currently revising driver setup. In general,
device driver will not work properly w/o bus being setup and the
only way to avoid explicit bus and simplify driver setup is to use
platform driver; however, we are not aware of any explicit dependency
on the platform, so not sure whether it's acceptable to switch to
platform device driver setup.
>
>> +
>> +static void mausb_remove(void)
>> +{
>> + struct usb_hcd *hcd, *shared_hcd;
>> +
>> + hcd = mhcd->hcd_hs_ctx->hcd;
>> + shared_hcd = mhcd->hcd_ss_ctx->hcd;
>> +
>> + if (shared_hcd) {
>> + usb_remove_hcd(shared_hcd);
>> + usb_put_hcd(shared_hcd);
>> + mhcd->hcd_ss_ctx = NULL;
>> + }
>> +
>> + usb_remove_hcd(hcd);
>> + usb_put_hcd(hcd);
>> + mhcd->hcd_hs_ctx = NULL;
>> +}
>> +
>> +static int mausb_bus_match(struct device *dev, struct device_driver *drv)
>> +{
>> + if (strncmp(dev->bus->name, drv->name, strlen(drv->name)))
>> + return 0;
>> + else
>> + return 1;
>> +}
>> +
>> +int mausb_init_hcd(void)
>> +{
>> + int retval = register_chrdev(0, DEVICE_NAME, &mausb_fops);
>> +
>> + if (retval < 0)
>> + return retval;
>> +
>> + major = (unsigned int)retval;
>> + retval = bus_register(&mausb_bus_type);
>> + if (retval)
>> + goto bus_register_error;
>> +
>> + mausb_class = class_create(THIS_MODULE, CLASS_NAME);
>> + if (IS_ERR(mausb_class)) {
>> + retval = (int)PTR_ERR(mausb_class);
>> + goto class_error;
>> + }
>> +
>> + retval = driver_register(&mausb_driver);
>> + if (retval)
>> + goto driver_register_error;
>> +
>> + mhcd = kzalloc(sizeof(*mhcd), GFP_ATOMIC);
>> + if (!mhcd) {
>> + retval = -ENOMEM;
>> + goto mausb_hcd_alloc_failed;
>> + }
>> +
>> + devt = MKDEV(major, minor);
>> + device = device_create(mausb_class, NULL, devt, mhcd, DEVICE_NAME);
>> + if (IS_ERR(device)) {
>> + retval = (int)IS_ERR(device);
>> + goto device_create_error;
>> + }
>> +
>> + device->driver = &mausb_driver;
>
> Why? What is this device going to do? What do you need it for?
Yeah, this one is not needed at all. Will be removed.
>
>> +
>> + return retval;
>> +device_create_error:
>> + kfree(mhcd);
>> + mhcd = NULL;
>> +mausb_hcd_alloc_failed:
>> + driver_unregister(&mausb_driver);
>> +driver_register_error:
>> + class_destroy(mausb_class);
>> +class_error:
>> + bus_unregister(&mausb_bus_type);
>> +bus_register_error:
>> + unregister_chrdev(major, DEVICE_NAME);
>
> I thought you were using the misc device, what are you doing with a
> class and chardev? Why is that still here?
>
We're currently revising driver setup logic - this part should be much
cleaner in new patch version.
>
>
>
>> +
>> + return retval;
>> +}
>> +
>> +void mausb_deinit_hcd(void)
>> +{
>> + if (mhcd) {
>> + mausb_remove();
>> + device_destroy(mausb_class, devt);
>> + driver_unregister(&mausb_driver);
>> + class_destroy(mausb_class);
>> + bus_unregister(&mausb_bus_type);
>> + unregister_chrdev(major, DEVICE_NAME);
>> + }
>> +}
>> diff --git a/drivers/usb/host/mausb/hcd.h b/drivers/usb/host/mausb/hcd.h
>> new file mode 100644
>> index 000000000000..e2374af67663
>> --- /dev/null
>> +++ b/drivers/usb/host/mausb/hcd.h
>> @@ -0,0 +1,65 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
>> + */
>> +#ifndef __MAUSB_HCD_H__
>> +#define __MAUSB_HCD_H__
>> +
>> +#include <linux/slab.h>
>> +#include <linux/usb.h>
>> +#include <linux/usb/hcd.h>
>> +
>> +#define DEVICE_NAME "mausb_host_hcd"
>> +#define CLASS_NAME "mausb"
>> +
>> +#define NUMBER_OF_PORTS 15
>
> Why this max?
Related to USB_SS_MAXPORTS - a worst case scenario.
>
>> +
>> +#define MAX_USB_DEVICE_DEPTH 6
>
> Where does this max come from?
Unknown origin and unused - will be removed.
>
>> +
>> +#define RESPONSE_TIMEOUT 5000
>
> Units?
ms - will be renamed to reflect the same.
>
>> +
>> +#define MAUSB_PORT_20_STATUS_LOW_SPEED 0x0200
>> +#define MAUSB_PORT_20_STATUS_HIGH_SPEED 0x0400
>
> Device ids? Something else?
>
> If something else, use BIT()?
>
>> +
>> +enum mausb_device_type {
>> + USBDEVICE = 0,
>> + USB20HUB = 1,
>> + USB30HUB = 2
>
> Trailing , please
>
>> +};
>> +
>> +enum mausb_device_speed {
>> + LOW_SPEED = 0,
>> + FULL_SPEED = 1,
>> + HIGH_SPEED = 2,
>> + SUPER_SPEED = 3,
>> + SUPER_SPEED_PLUS = 4
>
> , please.
>
>> +};
>
> Where do these values come from?
>
>> +
>> +struct mausb_hcd {
>> + spinlock_t lock; /* Protect HCD during URB processing */
>> + struct device *pdev;
>> + u16 connected_ports;
>
> Why u16?
Seems odd, since max number of ports is much less. Should be corrected.
>
>> +
>> + struct rb_root mausb_urbs;
>> + struct hub_ctx *hcd_ss_ctx;
>> + struct hub_ctx *hcd_hs_ctx;
>> + struct notifier_block power_state_listener;
>> +};
>> +
>> +struct mausb_dev {
>> + u32 port_status;
>> + struct rb_root usb_devices;
>> + u8 dev_speed;
>> + void *ma_dev;
>> +};
>> +
>> +struct hub_ctx {
>> + struct mausb_hcd *mhcd;
>> + struct usb_hcd *hcd;
>> + struct mausb_dev ma_devs[NUMBER_OF_PORTS];
>> +};
>> +
>> +int mausb_init_hcd(void);
>> +void mausb_deinit_hcd(void);
>> +
>> +#endif /* __MAUSB_HCD_H__ */
>> diff --git a/drivers/usb/host/mausb/mausb_core.c b/drivers/usb/host/mausb/mausb_core.c
>> index 44f76a1b74de..485f241d2b4c 100644
>> --- a/drivers/usb/host/mausb/mausb_core.c
>> +++ b/drivers/usb/host/mausb/mausb_core.c
>> @@ -4,6 +4,7 @@
>> */
>> #include <linux/module.h>
>>
>> +#include "hcd.h"
>> #include "utils.h"
>>
>> MODULE_LICENSE("GPL");
>> @@ -11,12 +12,27 @@ MODULE_AUTHOR("DisplayLink (UK) Ltd.");
>>
>> static int mausb_host_init(void)
>> {
>> - return mausb_host_dev_register();
>> + int status = mausb_host_dev_register();
>> +
>> + if (status < 0)
>> + goto exit;
>> +
>> + status = mausb_init_hcd();
>> + if (status < 0)
>> + goto cleanup_dev;
>> +
>> + return 0;
>> +
>> +cleanup_dev:
>> + mausb_host_dev_deregister();
>> +exit:
>> + return status;
>> }
>>
>> static void mausb_host_exit(void)
>> {
>> dev_info(mausb_host_dev.this_device, "Module unloading started...");
>
> This is debugging statements, please remove. If a driver works
> properly, it does not print anything out.
>
> Especially as you never give the user the chance to see if module
> unloading ever finished :)
Agree :)
>
> thanks,
>
> greg k-h
>
--
Regards,
Vladimir.
