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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 5A2A7C282CE for ; Wed, 22 May 2019 16:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AC3620879 for ; Wed, 22 May 2019 16:41:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730144AbfEVQlk (ORCPT ); Wed, 22 May 2019 12:41:40 -0400 Received: from mga09.intel.com ([134.134.136.24]:4136 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729572AbfEVQlj (ORCPT ); Wed, 22 May 2019 12:41:39 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 May 2019 09:41:39 -0700 X-ExtLoop1: 1 Received: from sydneywa-mobl1.amr.corp.intel.com (HELO [10.252.132.240]) ([10.252.132.240]) by orsmga004.jf.intel.com with ESMTP; 22 May 2019 09:41:38 -0700 Subject: Re: [PATCH] soundwire: stream: fix bad unlock balance To: Srinivas Kandagatla , vkoul@kernel.org Cc: sanyog.r.kale@intel.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org References: <20190522162528.5892-1-srinivas.kandagatla@linaro.org> From: Pierre-Louis Bossart Message-ID: <4744834c-36b1-dd8d-45fa-76c75eb3d5cb@linux.intel.com> Date: Wed, 22 May 2019 11:41:38 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190522162528.5892-1-srinivas.kandagatla@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/22/19 11:25 AM, Srinivas Kandagatla wrote: > This patch fixes below warning due to unlocking without locking. > > ===================================== > WARNING: bad unlock balance detected! > 5.1.0-16506-gc1c383a6f0a2-dirty #1523 Tainted: G W > ------------------------------------- > aplay/2954 is trying to release lock (&bus->msg_lock) at: > do_bank_switch+0x21c/0x480 > but there are no more locks to release! > > Signed-off-by: Srinivas Kandagatla > --- > drivers/soundwire/stream.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c > index 544925ff0b40..d16268f30e4f 100644 > --- a/drivers/soundwire/stream.c > +++ b/drivers/soundwire/stream.c > @@ -814,7 +814,8 @@ static int do_bank_switch(struct sdw_stream_runtime *stream) > goto error; > } > > - mutex_unlock(&bus->msg_lock); > + if (mutex_is_locked(&bus->msg_lock)) > + utex_unlock(&bus->msg_lock); Does this even compile? should be mutex_unlock, no? We also may want to identify the issue in more details without pushing it under the rug. The locking mechanism is far from simple and it's likely there are a number of problems with it. > } > > return ret; >