USB: consolidate usb_unbind_interface and usb_driver_release_interface

This patch (as1230) consolidates code in usb_unbind_interface() and
usb_driver_release_interface().  In fact, it makes release_interface
call unbind_interface, thereby removing the need for duplicated code.

It works like this: If the interface has already been registered with
the driver core when a driver releases it, then the usual driver-core
mechanism will call unbind_interface.  If it hasn't been unregistered
then we will make the call ourselves.

As a nice bonus, drivers now don't have to worry about whether their
disconnect method will get called when they release an interface -- it
always will.  Previously it would be called only if the interface was
registered.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 13 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index d0a21a5f8201..c115eed0fdc3 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -385,7 +385,6 @@ void usb_driver_release_interface(struct usb_driver *driver,
                                         struct usb_interface *iface)
 {
         struct device *dev = &iface->dev;
-        struct usb_device *udev = interface_to_usbdev(iface);
 
         /* this should never happen, don't release something that's not ours */
         if (!dev->driver || dev->driver != &driver->drvwrap.driver)
@@ -394,23 +393,19 @@ void usb_driver_release_interface(struct usb_driver *driver,
         /* don't release from within disconnect() */
         if (iface->condition != USB_INTERFACE_BOUND)
                 return;
+        iface->condition = USB_INTERFACE_UNBINDING;
 
-        /* don't release if the interface hasn't been added yet */
+        /* Release via the driver core only if the interface
+         * has already been registered
+         */
         if (device_is_registered(dev)) {
-                iface->condition = USB_INTERFACE_UNBINDING;
                 device_release_driver(dev);
         } else {
-                iface->condition = USB_INTERFACE_UNBOUND;
-                usb_cancel_queued_reset(iface);
+                down(&dev->sem);
+                usb_unbind_interface(dev);
+                dev->driver = NULL;
+                up(&dev->sem);
         }
-        dev->driver = NULL;
-        usb_set_intfdata(iface, NULL);
-
-        usb_pm_lock(udev);
-        iface->condition = USB_INTERFACE_UNBOUND;
-        mark_quiesced(iface);
-        iface->needs_remote_wakeup = 0;
-        usb_pm_unlock(udev);
 }
 EXPORT_SYMBOL_GPL(usb_driver_release_interface);