netxen: fix race in tx ring acccess

Fix the distance check between tx ring producer and consumer that
could lead to tx ring wrap around.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 5d79c19a6ec0..6a496b1909eb 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -809,6 +809,7 @@ netxen_nic_down(struct netxen_adapter *adapter, struct net_device *netdev)
 {
         netif_carrier_off(netdev);
         netif_stop_queue(netdev);
+        smp_mb();
         netxen_napi_disable(adapter);
 
         if (adapter->stop_port)
@@ -1340,7 +1341,7 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         producer = tx_ring->producer;
         smp_mb();
         consumer = tx_ring->sw_consumer;
-        if ((no_of_desc+2) > find_diff_among(producer, consumer, num_txd)) {
+        if ((no_of_desc+2) >= find_diff_among(producer, consumer, num_txd)) {
                 netif_stop_queue(netdev);
                 smp_mb();
                 return NETDEV_TX_BUSY;