From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E80EC433DF for ; Wed, 12 Aug 2020 04:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7711C2078B for ; Wed, 12 Aug 2020 04:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597205804; bh=dDly0umphm6eP9IgKi/bR1Xe7oJc3DuJ9fqY6LBtYDM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=lA/Q+fiGeONCoxQIYodFJbAqJmYLqdcgiVCYZonS0gQSDKlFntS9yEPQQAyMoWgga FyPIluKqXU3u0i4GCYbXpy1+kloJFwOn4liu9gyTR0CFGCu7sII4FWyeuisLQodiLX Ylo414JENlY794tvT7gwvO6vbaPTPZU/xL1b/hwo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726558AbgHLEQn (ORCPT ); Wed, 12 Aug 2020 00:16:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:42106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725874AbgHLEQn (ORCPT ); Wed, 12 Aug 2020 00:16:43 -0400 Received: from localhost (unknown [122.171.202.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6ED7820675; Wed, 12 Aug 2020 04:16:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597205802; bh=dDly0umphm6eP9IgKi/bR1Xe7oJc3DuJ9fqY6LBtYDM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VeowWUTysyFtRAIrl0D4aCP0IHl0b5n89L2/ZZ2LePcAZ17DbiBC3rafcEvn5ZcJK XXJy+0wYqEpgSzeqhowquInzzTMHLic6eZDtjkVFYcr7zmYtqQsMzXaj1w2vkcdI13 Ecg+eLXiysn80D9+v2fJ74bqqnYiT5FNtlwZUPOU= Date: Wed, 12 Aug 2020 09:46:38 +0530 From: Vinod Koul To: Laurent Pinchart Cc: kernel test robot , Hyun Kwon , kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, Tejas Upadhyay , Michal Simek Subject: Re: drivers/dma/xilinx/xilinx_dpdma.c:1172 xilinx_dpdma_synchronize() error: double unlocked 'chan->vchan.lock' (orig line 1170) Message-ID: <20200812041638.GT12965@vkoul-mobl> References: <202008120657.drkFgIsC%lkp@intel.com> <20200811225006.GF17446@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200811225006.GF17446@pendragon.ideasonboard.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org HI Laurent, On 12-08-20, 01:50, Laurent Pinchart wrote: > On Wed, Aug 12, 2020 at 06:37:59AM +0800, kernel test robot wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > head: c636eef2ee3696f261a35f34989842701a107895 > > commit: 7cbb0c63de3fc218fd06ecfedb477772a4d12f76 dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver > > date: 4 weeks ago > > config: h8300-randconfig-m031-20200811 (attached as .config) > > compiler: h8300-linux-gcc (GCC) 9.3.0 > > > > If you fix the issue, kindly add following tag as appropriate > > Reported-by: kernel test robot > > > > smatch warnings: > > drivers/dma/xilinx/xilinx_dpdma.c:1172 xilinx_dpdma_synchronize() error: double unlocked 'chan->vchan.lock' (orig line 1170) > > Unless I'm mistaken, this is a false positive. I'd appreciate if someone > could check if I'm missing something obvious. > > > vim +1172 drivers/dma/xilinx/xilinx_dpdma.c > > > > 1140 > > 1141 /** > > 1142 * xilinx_dpdma_synchronize - Synchronize callback execution > > 1143 * @dchan: DMA channel > > 1144 * > > 1145 * Synchronizing callback execution ensures that all previously issued > > 1146 * transfers have completed and all associated callbacks have been called and > > 1147 * have returned. > > 1148 * > > 1149 * This function waits for the DMA channel to stop. It assumes it has been > > 1150 * paused by a previous call to dmaengine_terminate_async(), and that no new > > 1151 * pending descriptors have been issued with dma_async_issue_pending(). The > > 1152 * behaviour is undefined otherwise. > > 1153 */ > > 1154 static void xilinx_dpdma_synchronize(struct dma_chan *dchan) > > 1155 { > > 1156 struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan); > > 1157 unsigned long flags; > > 1158 > > 1159 xilinx_dpdma_chan_stop(chan); > > 1160 > > 1161 spin_lock_irqsave(&chan->vchan.lock, flags); Lock is held here > > 1162 if (chan->desc.pending) { > > 1163 vchan_terminate_vdesc(&chan->desc.pending->vdesc); This should be called with lock held > > 1164 chan->desc.pending = NULL; > > 1165 } > > 1166 if (chan->desc.active) { > > 1167 vchan_terminate_vdesc(&chan->desc.active->vdesc); same here > > 1168 chan->desc.active = NULL; > > 1169 } > > > 1170 spin_unlock_irqrestore(&chan->vchan.lock, flags); Dropped > > 1171 > > > 1172 vchan_synchronize(&chan->vchan); This should be called without lock So I agree with you, looks like a false positive to me as well -- ~Vinod