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 ckeepax@opensource.wolfsonmicro.com --- 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)