Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753292Ab3IWFQN (ORCPT ); Mon, 23 Sep 2013 01:16:13 -0400 Received: from mga03.intel.com ([143.182.124.21]:57411 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753159Ab3IWFQM (ORCPT ); Mon, 23 Sep 2013 01:16:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.90,960,1371106800"; d="scan'208";a="298072094" Date: Mon, 23 Sep 2013 09:55:49 +0530 From: Vinod Koul To: Lu Jingchang-B35083 Cc: "djbw@fb.com" , "shawn.guo@linaro.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" Subject: Re: [PATCH 3/3] dma: Add Freescale eDMA engine driver support Message-ID: <20130923042549.GC17188@intel.com> References: <1378374799-16357-1-git-send-email-b35083@freescale.com> <20130917045359.GN17188@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 786 Lines: 19 On Tue, Sep 17, 2013 at 08:08:46AM +0000, Lu Jingchang-B35083 wrote: > > > + case DMA_PAUSE: > > > + if (fsl_chan->edesc) > > > + fsl_edma_disable_request(fsl_chan); > > racy here too... > It only set the channel HW register, no list is handled, > is lock needed here? Thanks! well thats the point while you are terminating the current trasnaction can complete and then start another one. You want to try and prevent these case also. Here you are neither locking the HW access nor the the list, so its juts waiting to crash! ~Vinod -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/