USB: usb peripheral controller driver oops avoidance

I'm having problem with oopses when rebooting, if I modprobe g_serial
and rmmod g_serial and do a reboot I get an oops in device_shutdown().
The reason seems to be that usb_gadget_unregister_driver() doesn't do
enough cleanup.  With this at91_udc patch I don't get the oops.

Signed-off-by: Patrik Sevallius <patrik.sevallius@enea.com>
[ Same bug was in other peripheral controller drivers; fixed ]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index cd62b029d176..4b6ed353ae36 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -1616,6 +1616,8 @@ int usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
         local_irq_enable();
 
         driver->unbind(&udc->gadget);
+        udc->gadget.dev.driver = NULL;
+        udc->gadget.dev.driver_data = NULL;
         udc->driver = NULL;
 
         DBG("unbound from %s\n", driver->driver.name);