From patchwork Tue Mar 9 16:55:02 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3/4] bnx2x: change smp_mb() comment to conform the true Date: Tue, 09 Mar 2010 06:55:02 -0000 From: Stanislaw Gruszka X-Patchwork-Id: 47174 Message-Id: <1268153703-4186-3-git-send-email-sgruszka@redhat.com> To: netdev@vger.kernel.org Cc: Vladislav Zolotarov , Eilon Greenstein , Michael Chan , Stanislaw Gruszka Access to fp->tx_bp_prod is protected by __netif_tx_lock, smp_mb() is not needed for that. Signed-off-by: Stanislaw Gruszka Signed-off-by: Eilon Greenstein --- drivers/net/bnx2x_main.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c index ae62b67..6c042a7 100644 --- a/drivers/net/bnx2x_main.c +++ b/drivers/net/bnx2x_main.c @@ -11428,9 +11428,12 @@ static netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev) if (unlikely(bnx2x_tx_avail(fp) < MAX_SKB_FRAGS + 3)) { netif_tx_stop_queue(txq); - /* We want bnx2x_tx_int to "see" the updated tx_bd_prod - if we put Tx into XOFF state. */ + + /* paired memory barrier is in bnx2x_tx_int(), we have to keep + * ordering of set_bit() in netif_tx_stop_queue() and read of + * fp->bd_tx_cons */ smp_mb(); + fp->eth_q_stats.driver_xoff++; if (bnx2x_tx_avail(fp) >= MAX_SKB_FRAGS + 3) netif_tx_wake_queue(txq);