Bluetooth: Wrong style spin lock used

Use spin_lock_bh() as the code is called from softirq in networking subsystem.
This is needed to prevent deadlocks when 6lowpan link is in use.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_core.c

@@ -4661,8 +4661,12 @@ static void hci_queue_acl(struct hci_chan *chan, struct sk_buff_head *queue,
 
 		skb_shinfo(skb)->frag_list = NULL;
 
-		/* Queue all fragments atomically */
-		spin_lock(&queue->lock);
+		/* Queue all fragments atomically. We need to use spin_lock_bh
+		 * here because of 6LoWPAN links, as there this function is
+		 * called from softirq and using normal spin lock could cause
+		 * deadlocks.
+		 */
+		spin_lock_bh(&queue->lock);
 
 		__skb_queue_tail(queue, skb);
 
@@ -4679,7 +4683,7 @@ static void hci_queue_acl(struct hci_chan *chan, struct sk_buff_head *queue,
 			__skb_queue_tail(queue, skb);
 		} while (list);
 
-		spin_unlock(&queue->lock);
+		spin_unlock_bh(&queue->lock);
 	}
 }