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;