From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: [PATCH 1/2] ASoC: Use nested lock for snd_soc_dapm_mutex_lock Date: Tue, 29 Dec 2015 16:25:13 +0000 Message-ID: <1451406314-13973-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx0b-001ae601.pphosted.com (mx0b-001ae601.pphosted.com [67.231.152.168]) by alsa0.perex.cz (Postfix) with ESMTP id A5B3D26586C for ; Tue, 29 Dec 2015 17:25:40 +0100 (CET) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: broonie@kernel.org Cc: alsa-devel@alsa-project.org, patches@opensource.wolfsonmicro.com, lgirdwood@gmail.com List-Id: alsa-devel@alsa-project.org snd_soc_dapm_mutex_lock currently uses the un-nested call which can cause lockdep warnings when called from control handlers (a relatively common usage) and using modules. As creating the control causes a potential mutex inversion with the handler, creating the control will take the controls_rwsem under the dapm_mutex and accessing the control will take the dapm_mutex under controls_rwsem. All the users look like they want to be using the runtime class of the lock anyway, so this patch just changes snd_soc_dapm_mutex_lock to use the nested call, with the SND_SOC_DAPM_CLASS_RUNTIME class. Fixes: f6d5e586b416 ("ASoC: dapm: Add helpers to lock/unlock DAPM mutex") Signed-off-by: Charles Keepax --- include/sound/soc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/sound/soc.h b/include/sound/soc.h index a2deeb9..aae55d0 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -1687,7 +1687,7 @@ extern const struct dev_pm_ops snd_soc_pm_ops; /* Helper functions */ static inline void snd_soc_dapm_mutex_lock(struct snd_soc_dapm_context *dapm) { - mutex_lock(&dapm->card->dapm_mutex); + mutex_lock_nested(&dapm->card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME); } static inline void snd_soc_dapm_mutex_unlock(struct snd_soc_dapm_context *dapm) -- 2.1.4