netxen: fix deadlock on dev close

netxen: fix deadlock on dev close

The tx ring accounting fix in commit cb2107be43d2fc5eadec58b92b
("netxen: fix tx ring accounting") introduced intermittent
deadlock when inteface is going down.

This was possibly combined effect of speculative tx pause,
calling netif_tx_lock instead of queue lock and unclean
synchronization with napi which could end up unmasking
interrupt.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/net/netxen/netxen_nic_hw.c b/drivers/net/netxen/netxen_nic_hw.c
index ce3b89d2cbb6..b9123d445c96 100644
--- a/drivers/net/netxen/netxen_nic_hw.c
+++ b/drivers/net/netxen/netxen_nic_hw.c
@@ -461,13 +461,14 @@ netxen_send_cmd_descs(struct netxen_adapter *adapter,
         i = 0;
 
         tx_ring = adapter->tx_ring;
-        netif_tx_lock_bh(adapter->netdev);
+        __netif_tx_lock_bh(tx_ring->txq);
 
         producer = tx_ring->producer;
         consumer = tx_ring->sw_consumer;
 
-        if (nr_desc >= find_diff_among(producer, consumer, tx_ring->num_desc)) {
-                netif_tx_unlock_bh(adapter->netdev);
+        if (nr_desc >= netxen_tx_avail(tx_ring)) {
+                netif_tx_stop_queue(tx_ring->txq);
+                __netif_tx_unlock_bh(tx_ring->txq);
                 return -EBUSY;
         }
 
@@ -490,7 +491,7 @@ netxen_send_cmd_descs(struct netxen_adapter *adapter,
 
         netxen_nic_update_cmd_producer(adapter, tx_ring);
 
-        netif_tx_unlock_bh(adapter->netdev);
+        __netif_tx_unlock_bh(tx_ring->txq);
 
         return 0;
 }