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

[Aditya Garg <gargaditya08@live.com>]

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