Re: [PATCH] USB: core: add 'shutdown' callback to usb_driver

[Aditya Garg <gargaditya08@live.com>]

Replying to this since I forgot to add the author Kerem Karabay to cc, so adding now

> On 5 Jul 2024, at 4:50 PM, Aditya Garg <gargaditya08@live.com> wrote:
> 
> From: Kerem Karabay <kekrby@gmail.com>
> 
> This simplifies running code on shutdown for USB drivers.
> 
> Signed-off-by: Kerem Karabay <kekrby@gmail.com>
> Signed-off-by: Aditya Garg <gargaditya08@live.com>
> ---
> drivers/usb/core/driver.c | 14 ++++++++++++++
> drivers/usb/storage/uas.c |  5 ++---
> include/linux/usb.h       |  3 +++
> 3 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
> index f58a0299f..dc0f86376 100644
> --- a/drivers/usb/core/driver.c
> +++ b/drivers/usb/core/driver.c
> @@ -514,6 +514,19 @@ static int usb_unbind_interface(struct device *dev)
> 	return 0;
> }
> 
> +static void usb_shutdown_interface(struct device *dev)
> +{
> +	struct usb_interface *intf = to_usb_interface(dev);
> +	struct usb_driver *driver;
> +
> +	if (!dev->driver)
> +		return;
> +
> +	driver = to_usb_driver(dev->driver);
> +	if (driver->shutdown)
> +		driver->shutdown(intf);
> +}
> +
> /**
>  * usb_driver_claim_interface - bind a driver to an interface
>  * @driver: the driver to be bound
> @@ -1053,6 +1066,7 @@ int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
> 	new_driver->driver.bus = &usb_bus_type;
> 	new_driver->driver.probe = usb_probe_interface;
> 	new_driver->driver.remove = usb_unbind_interface;
> +	new_driver->driver.shutdown = usb_shutdown_interface;
> 	new_driver->driver.owner = owner;
> 	new_driver->driver.mod_name = mod_name;
> 	new_driver->driver.dev_groups = new_driver->dev_groups;
> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
> index 2583ee981..591fa0379 100644
> --- a/drivers/usb/storage/uas.c
> +++ b/drivers/usb/storage/uas.c
> @@ -1221,9 +1221,8 @@ static void uas_disconnect(struct usb_interface *intf)
>  * hang on reboot when the device is still in uas mode. Note the reset is
>  * necessary as some devices won't revert to usb-storage mode without it.
>  */
> -static void uas_shutdown(struct device *dev)
> +static void uas_shutdown(struct usb_interface *intf)
> {
> -	struct usb_interface *intf = to_usb_interface(dev);
> 	struct usb_device *udev = interface_to_usbdev(intf);
> 	struct Scsi_Host *shost = usb_get_intfdata(intf);
> 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
> @@ -1246,7 +1245,7 @@ static struct usb_driver uas_driver = {
> 	.suspend = uas_suspend,
> 	.resume = uas_resume,
> 	.reset_resume = uas_reset_resume,
> -	.driver.shutdown = uas_shutdown,
> +	.shutdown = uas_shutdown,
> 	.id_table = uas_usb_ids,
> };
> 
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index 25f8e62a3..5f3ae2186 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -1194,6 +1194,7 @@ struct usbdrv_wrap {
>  *	post_reset method is called.
>  * @post_reset: Called by usb_reset_device() after the device
>  *	has been reset
> + * @shutdown: Called at shut-down time to quiesce the device.
>  * @id_table: USB drivers use ID table to support hotplugging.
>  *	Export this with MODULE_DEVICE_TABLE(usb,...).  This must be set
>  *	or your driver's probe function will never get called.
> @@ -1245,6 +1246,8 @@ struct usb_driver {
> 	int (*pre_reset)(struct usb_interface *intf);
> 	int (*post_reset)(struct usb_interface *intf);
> 
> +	void (*shutdown)(struct usb_interface *intf);
> +
> 	const struct usb_device_id *id_table;
> 	const struct attribute_group **dev_groups;
> 
> -- 
> 2.42.0
>