From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932668Ab1ALN3x (ORCPT ); Wed, 12 Jan 2011 08:29:53 -0500 Received: from mail.atmel.fr ([81.80.104.162]:36333 "EHLO atmel-es2.atmel.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932419Ab1ALN3O (ORCPT ); Wed, 12 Jan 2011 08:29:14 -0500 From: Nicolas Ferre To: dan.j.williams@intel.com, linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, hong.xu@atmel.com, Nicolas Ferre Subject: [PATCH 6/6] dmaengine: at_hdmac: fix race while monitoring channel status Date: Wed, 12 Jan 2011 15:39:10 +0100 Message-Id: <1294843150-6962-5-git-send-email-nicolas.ferre@atmel.com> X-Mailer: git-send-email 1.7.3 In-Reply-To: <1292435416-16927-1-git-send-email-nicolas.ferre@atmel.com> References: <1292435416-16927-1-git-send-email-nicolas.ferre@atmel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We were reading channel status then taking a lock. This lead to a race because this lock may delay us and then make this channel not idle anymore. Signed-off-by: Nicolas Ferre --- drivers/dma/at_hdmac.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 99942a5..3d7d705 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -853,11 +853,11 @@ static void atc_issue_pending(struct dma_chan *chan) dev_vdbg(chan2dev(chan), "issue_pending\n"); + spin_lock_bh(&atchan->lock); if (!atc_chan_is_enabled(atchan)) { - spin_lock_bh(&atchan->lock); atc_advance_work(atchan); - spin_unlock_bh(&atchan->lock); } + spin_unlock_bh(&atchan->lock); } /** -- 1.7.3