From patchwork Sun Mar 18 12:18:07 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yevgeny Petrilin X-Patchwork-Id: 147373 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 62031B6FA2 for ; Sun, 18 Mar 2012 23:18:21 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752744Ab2CRMSP (ORCPT ); Sun, 18 Mar 2012 08:18:15 -0400 Received: from eu1sys200aog103.obsmtp.com ([207.126.144.115]:36016 "HELO eu1sys200aog103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751087Ab2CRMSN (ORCPT ); Sun, 18 Mar 2012 08:18:13 -0400 Received: from MTLCAS01.mtl.com ([194.90.237.34]) (using TLSv1) by eu1sys200aob103.postini.com ([207.126.147.11]) with SMTP ID DSNKT2XSgS8j34esGFnwaNT7c7ttxkpNxEC0@postini.com; Sun, 18 Mar 2012 12:18:12 UTC Received: from [10.4.45.17] (10.0.13.1) by MTLCAS01.mtl.com (10.0.8.71) with Microsoft SMTP Server id 14.2.247.3; Sun, 18 Mar 2012 14:18:07 +0200 Message-ID: <4F65D27F.7010102@mellanox.co.il> Date: Sun, 18 Mar 2012 14:18:07 +0200 From: Yevgeny Petrilin User-Agent: Thunderbird 2.0.0.17 (X11/20080914) MIME-Version: 1.0 To: CC: , , Subject: [PATCH net] mlx4_core: fix race on comm channel X-Originating-IP: [10.0.13.1] Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eugenia Emantayev Prevent race condition between commands on comm channel. Happened while unloading the driver when switching from event to polling mode. VF got completion on the last command before switching to polling mode, but toggle was not changed. After the fix - VF will not write the next command before toggle is updated. Signed-off-by: Eugenia Emantayev --- drivers/net/ethernet/mellanox/mlx4/cmd.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c index eaf09d4..2f1f4a1 100644 --- a/drivers/net/ethernet/mellanox/mlx4/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c @@ -239,6 +239,7 @@ static int mlx4_comm_cmd_wait(struct mlx4_dev *dev, u8 op, { struct mlx4_cmd *cmd = &mlx4_priv(dev)->cmd; struct mlx4_cmd_context *context; + unsigned long end; int err = 0; down(&cmd->event_sem); @@ -268,6 +269,13 @@ static int mlx4_comm_cmd_wait(struct mlx4_dev *dev, u8 op, } out: + /* wait for comm channel ready + this is necessary for prevention the race + when switching between event to polling mode */ + end = msecs_to_jiffies(timeout) + jiffies; + while (comm_pending(dev) && time_before(jiffies, end)) + cond_resched(); + spin_lock(&cmd->context_lock); context->next = cmd->free_head; cmd->free_head = context - cmd->context;