netdev: Fix lockdep warnings in multiqueue configurations.

When support for multiple TX queues were added, the
netif_tx_lock() routines we converted to iterate over
all TX queues and grab each queue's spinlock.

This causes heartburn for lockdep and it's not a healthy
thing to do with lots of TX queues anyways.

So modify this to use a top-level lock and a "frozen"
state for the individual TX queues.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 0960e69b2da4..e4fbefc8c82f 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -69,18 +69,20 @@ static void ri_tasklet(unsigned long dev)
 	struct net_device *_dev = (struct net_device *)dev;
 	struct ifb_private *dp = netdev_priv(_dev);
 	struct net_device_stats *stats = &_dev->stats;
+	struct netdev_queue *txq;
 	struct sk_buff *skb;
 
+	txq = netdev_get_tx_queue(_dev, 0);
 	dp->st_task_enter++;
 	if ((skb = skb_peek(&dp->tq)) == NULL) {
 		dp->st_txq_refl_try++;
-		if (netif_tx_trylock(_dev)) {
+		if (__netif_tx_trylock(txq)) {
 			dp->st_rxq_enter++;
 			while ((skb = skb_dequeue(&dp->rq)) != NULL) {
 				skb_queue_tail(&dp->tq, skb);
 				dp->st_rx2tx_tran++;
 			}
-			netif_tx_unlock(_dev);
+			__netif_tx_unlock(txq);
 		} else {
 			/* reschedule */
 			dp->st_rxq_notenter++;
@@ -115,7 +117,7 @@ static void ri_tasklet(unsigned long dev)
 			BUG();
 	}
 
-	if (netif_tx_trylock(_dev)) {
+	if (__netif_tx_trylock(txq)) {
 		dp->st_rxq_check++;
 		if ((skb = skb_peek(&dp->rq)) == NULL) {
 			dp->tasklet_pending = 0;
@@ -123,10 +125,10 @@ static void ri_tasklet(unsigned long dev)
 				netif_wake_queue(_dev);
 		} else {
 			dp->st_rxq_rsch++;
-			netif_tx_unlock(_dev);
+			__netif_tx_unlock(txq);
 			goto resched;
 		}
-		netif_tx_unlock(_dev);
+		__netif_tx_unlock(txq);
 	} else {
 resched:
 		dp->tasklet_pending = 1;