From patchwork Sun Mar 18 14:32:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yevgeny Petrilin X-Patchwork-Id: 147389 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 33840B6FAB for ; Mon, 19 Mar 2012 01:32:17 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754006Ab2CROcO (ORCPT ); Sun, 18 Mar 2012 10:32:14 -0400 Received: from eu1sys200aog118.obsmtp.com ([207.126.144.145]:39533 "HELO eu1sys200aog118.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753680Ab2CROcN (ORCPT ); Sun, 18 Mar 2012 10:32:13 -0400 Received: from MTLCAS02.mtl.com ([194.90.237.34]) (using TLSv1) by eu1sys200aob118.postini.com ([207.126.147.11]) with SMTP ID DSNKT2Xx6XJhNfKS4vLDbI3GpLyyfEbb+8zQ@postini.com; Sun, 18 Mar 2012 14:32:12 UTC Received: from [10.4.45.17] (10.0.13.1) by MTLCAS02.mtl.com (10.0.8.72) with Microsoft SMTP Server id 14.2.247.3; Sun, 18 Mar 2012 16:32:08 +0200 Message-ID: <4F65F1E8.9000505@mellanox.co.il> Date: Sun, 18 Mar 2012 16:32:08 +0200 From: Yevgeny Petrilin User-Agent: Thunderbird 2.0.0.17 (X11/20080914) MIME-Version: 1.0 To: CC: , , Subject: [PATCH net V1] 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 --- Diff from V0: Fixed comments style drivers/net/ethernet/mellanox/mlx4/cmd.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c index eaf09d4..6037d36 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 +269,14 @@ 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;