1 files changed, 28 insertions, 11 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index e0498571ae26..b4cf10781348 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -428,12 +428,18 @@ static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 	old_state = entry->state;
 	entry->state = state;
 	__skb_unlink(skb, list);
-	spin_unlock(&list->lock);
-	spin_lock(&dev->done.lock);
+
+	/* defer_bh() is never called with list == &dev->done.
+	 * spin_lock_nested() tells lockdep that it is OK to take
+	 * dev->done.lock here with list->lock held.
+	 */
+	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
+
 	__skb_queue_tail(&dev->done, skb);
 	if (dev->done.qlen == 1)
 		tasklet_schedule(&dev->bh);
-	spin_unlock_irqrestore(&dev->done.lock, flags);
+	spin_unlock(&dev->done.lock);
+	spin_unlock_irqrestore(&list->lock, flags);
 	return old_state;
 }
 
@@ -749,6 +755,20 @@ EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 
 /*-------------------------------------------------------------------------*/
 
+static void wait_skb_queue_empty(struct sk_buff_head *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->lock, flags);
+	while (!skb_queue_empty(q)) {
+		spin_unlock_irqrestore(&q->lock, flags);
+		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		spin_lock_irqsave(&q->lock, flags);
+	}
+	spin_unlock_irqrestore(&q->lock, flags);
+}
+
 // precondition: never called in_interrupt
 static void usbnet_terminate_urbs(struct usbnet *dev)
 {
@@ -762,14 +782,11 @@ static void usbnet_terminate_urbs(struct usbnet *dev)
 		unlink_urbs(dev, &dev->rxq);
 
 	/* maybe wait for deletions to finish. */
-	while (!skb_queue_empty(&dev->rxq)
-		&& !skb_queue_empty(&dev->txq)
-		&& !skb_queue_empty(&dev->done)) {
-			schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			netif_dbg(dev, ifdown, dev->net,
-				  "waited for %d urb completions\n", temp);
-	}
+	wait_skb_queue_empty(&dev->rxq);
+	wait_skb_queue_empty(&dev->txq);
+	wait_skb_queue_empty(&dev->done);
+	netif_dbg(dev, ifdown, dev->net,
+		  "waited for %d urb completions\n", temp);
 	set_current_state(TASK_RUNNING);
 	remove_wait_queue(&dev->wait, &wait);
 }