From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislaw Gruszka Subject: [PATCH 3/4] bnx2x: change smp_mb() comment to conform the true Date: Tue, 9 Mar 2010 17:55:02 +0100 Message-ID: <1268153703-4186-3-git-send-email-sgruszka@redhat.com> References: <1268153703-4186-1-git-send-email-sgruszka@redhat.com> <1268153703-4186-2-git-send-email-sgruszka@redhat.com> Cc: Vladislav Zolotarov , Eilon Greenstein , Michael Chan , Stanislaw Gruszka To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:28942 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755106Ab0CIQ44 (ORCPT ); Tue, 9 Mar 2010 11:56:56 -0500 In-Reply-To: <1268153703-4186-2-git-send-email-sgruszka@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Access to fp->tx_bp_prod is protected by __netif_tx_lock, smp_mb() is not needed for that. Signed-off-by: Stanislaw Gruszka --- 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); -- 1.6.2.5