Commit 4388d983 authored by Charles Keepax's avatar Charles Keepax Committed by Luis Henriques

ASoC: Use nested lock for snd_soc_dapm_mutex_lock

commit 783513ee upstream.

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: f6d5e586 ("ASoC: dapm: Add helpers to lock/unlock DAPM mutex")
Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent fdc08799
...@@ -1390,7 +1390,7 @@ extern const struct dev_pm_ops snd_soc_pm_ops; ...@@ -1390,7 +1390,7 @@ extern const struct dev_pm_ops snd_soc_pm_ops;
/* Helper functions */ /* Helper functions */
static inline void snd_soc_dapm_mutex_lock(struct snd_soc_dapm_context *dapm) 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) static inline void snd_soc_dapm_mutex_unlock(struct snd_soc_dapm_context *dapm)
......
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