USB: dummy-hcd: disable interrupts during req->complete

This patch (as756) fixes a bug in dummy-hcd found by the lockdep
checker.  In one of the code paths, the driver did not disable
interrupts before calling a request completion routine.

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

drivers/usb/gadget/dummy_hcd.c

@@ -609,7 +609,8 @@ static int dummy_dequeue (struct usb_ep *_ep, struct usb_request *_req)
 	if (!dum->driver)
 		return -ESHUTDOWN;
 
-	spin_lock_irqsave (&dum->lock, flags);
+	local_irq_save (flags);
+	spin_lock (&dum->lock);
 	list_for_each_entry (req, &ep->queue, queue) {
 		if (&req->req == _req) {
 			list_del_init (&req->queue);
@@ -618,14 +619,15 @@ static int dummy_dequeue (struct usb_ep *_ep, struct usb_request *_req)
 			break;
 		}
 	}
-	spin_unlock_irqrestore (&dum->lock, flags);
+	spin_unlock (&dum->lock);
 
 	if (retval == 0) {
 		dev_dbg (udc_dev(dum),
 				"dequeued req %p from %s, len %d buf %p\n",
 				req, _ep->name, _req->length, _req->buf);
 		_req->complete (_ep, _req);
 	}
+	local_irq_restore (flags);
 	return retval;
 }