ixgb: maybe stop tx port missed a piece

back when maybe stop tx was added to the ixgb driver some mistakes
were made and the driver
a) didn't remove the tx lock, which is now un-necessary
b) didn't change the restart code to be compliant with maybe_stop

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index 41f3adf5f375..04cac41f7d5e 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1855,12 +1855,17 @@ ixgb_clean_tx_irq(struct ixgb_adapter *adapter)
 
         tx_ring->next_to_clean = i;
 
-        if (unlikely(netif_queue_stopped(netdev))) {
-                spin_lock(&adapter->tx_lock);
-                if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev) &&
-                    (IXGB_DESC_UNUSED(tx_ring) >= DESC_NEEDED))
+        if (unlikely(cleaned && netif_carrier_ok(netdev) &&
+                     IXGB_DESC_UNUSED(tx_ring) >= DESC_NEEDED)) {
+                /* Make sure that anybody stopping the queue after this
+                 * sees the new next_to_clean. */
+                smp_mb();
+
+                if (netif_queue_stopped(netdev) &&
+                    !(test_bit(__IXGB_DOWN, &adapter->flags))) {
                         netif_wake_queue(netdev);
-                spin_unlock(&adapter->tx_lock);
+                        ++adapter->restart_queue;
+                }
         }
 
         if(adapter->detect_tx_hung) {