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>

2 files changed, 9 insertions, 6 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 345838a2e369..9c9cd4d94890 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -135,7 +135,8 @@ static inline int qdisc_restart(struct Qdisc *q)
         txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
 
         HARD_TX_LOCK(dev, txq, smp_processor_id());
-        if (!netif_subqueue_stopped(dev, skb))
+        if (!netif_tx_queue_stopped(txq) &&
+            !netif_tx_queue_frozen(txq))
                 ret = dev_hard_start_xmit(skb, dev, txq);
         HARD_TX_UNLOCK(dev, txq);
 
@@ -162,7 +163,8 @@ static inline int qdisc_restart(struct Qdisc *q)
                 break;
         }
 
-        if (ret && netif_tx_queue_stopped(txq))
+        if (ret && (netif_tx_queue_stopped(txq) ||
+                    netif_tx_queue_frozen(txq)))
                 ret = 0;
 
         return ret;
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index 537223642b6e..2c35c678563b 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -305,10 +305,11 @@ restart:
 
                 switch (teql_resolve(skb, skb_res, slave)) {
                 case 0:
-                        if (netif_tx_trylock(slave)) {
-                                if (!__netif_subqueue_stopped(slave, subq) &&
+                        if (__netif_tx_trylock(slave_txq)) {
+                                if (!netif_tx_queue_stopped(slave_txq) &&
+                                    !netif_tx_queue_frozen(slave_txq) &&
                                     slave->hard_start_xmit(skb, slave) == 0) {
-                                        netif_tx_unlock(slave);
+                                        __netif_tx_unlock(slave_txq);
                                         master->slaves = NEXT_SLAVE(q);
                                         netif_wake_queue(dev);
                                         master->stats.tx_packets++;
@@ -316,7 +317,7 @@ restart:
                                                 qdisc_pkt_len(skb);
                                         return 0;
                                 }
-                                netif_tx_unlock(slave);
+                                __netif_tx_unlock(slave_txq);
                         }
                         if (netif_queue_stopped(dev))
                                 busy = 1;