USB: whci-hcd: make endpoint_reset method async

usb_hcd_endpoint_reset() may be called in atomic context and must not
sleep.  So make whci-hcd's endpoint_reset() asynchronous.  URBs
submitted while the reset is in progress will be queued (on the std
list) and transfers will resume once the reset is complete.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/whci/pzl.c

@@ -255,11 +255,21 @@ void scan_periodic_work(struct work_struct *work)
 	/*
 	 * Now that the PZL is updated, complete the removal of any
 	 * removed qsets.
+	 *
+	 * If the qset was to be reset, do so and reinsert it into the
+	 * PZL if it has pending transfers.
 	 */
 	spin_lock_irq(&whc->lock);
 
 	list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
 		qset_remove_complete(whc, qset);
+		if (qset->reset) {
+			qset_reset(whc, qset);
+			if (!list_empty(&qset->stds)) {
+				qset_insert_in_sw_list(whc, qset);
+				queue_work(whc->workqueue, &whc->periodic_work);
+			}
+		}
 	}
 
 	spin_unlock_irq(&whc->lock);
@@ -295,7 +305,7 @@ int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 	else
 		err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 	if (!err) {
-		if (!qset->in_sw_list)
+		if (!qset->in_sw_list && !qset->remove)
 			qset_insert_in_sw_list(whc, qset);
 	} else
 		usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);