[PATCH] netpoll: fix netpoll lockup

current -git doesnt boot on my laptop due to netpoll not unlocking the
tx lock in the else branch.

booted this up on my laptop with lockdep enabled and there are no
locking complaints and it works fine.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

net/core/netpoll.c

@@ -55,6 +55,7 @@ static void queue_process(struct work_struct *work)
 	struct netpoll_info *npinfo =
 		container_of(work, struct netpoll_info, tx_work.work);
 	struct sk_buff *skb;
+	unsigned long flags;
 
 	while ((skb = skb_dequeue(&npinfo->txq))) {
 		struct net_device *dev = skb->dev;
@@ -64,15 +65,19 @@ static void queue_process(struct work_struct *work)
 			continue;
 		}
 
-		netif_tx_lock_bh(dev);
+		local_irq_save(flags);
+		netif_tx_lock(dev);
 		if (netif_queue_stopped(dev) ||
 		    dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) {
 			skb_queue_head(&npinfo->txq, skb);
-			netif_tx_unlock_bh(dev);
+			netif_tx_unlock(dev);
+			local_irq_restore(flags);
 
 			schedule_delayed_work(&npinfo->tx_work, HZ/10);
 			return;
 		}
+		netif_tx_unlock(dev);
+		local_irq_restore(flags);
 	}
 }