bnx2x: Reduce the likelihood of smb_mb
As the comment explains, this smb_mb is needed only if the queue is stopped
(which is unlikely) so the barrier can be moved to that location
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index 5954bed..fbd0f88 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -916,18 +916,19 @@
fp->tx_pkt_cons = sw_cons;
fp->tx_bd_cons = bd_cons;
- /* Need to make the tx_bd_cons update visible to start_xmit()
- * before checking for netif_tx_queue_stopped(). Without the
- * memory barrier, there is a small possibility that start_xmit()
- * will miss it and cause the queue to be stopped forever.
- */
- smp_mb();
-
/* TBD need a thresh? */
if (unlikely(netif_tx_queue_stopped(txq))) {
__netif_tx_lock(txq, smp_processor_id());
+ /* Need to make the tx_bd_cons update visible to start_xmit()
+ * before checking for netif_tx_queue_stopped(). Without the
+ * memory barrier, there is a small possibility that
+ * start_xmit() will miss it and cause the queue to be stopped
+ * forever.
+ */
+ smp_mb();
+
if ((netif_tx_queue_stopped(txq)) &&
(bp->state == BNX2X_STATE_OPEN) &&
(bnx2x_tx_avail(fp) >= MAX_SKB_FRAGS + 3))