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| author | Takashi Iwai <tiwai@suse.de> | 2014-10-21 17:32:13 +0400 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2014-10-21 20:17:02 +0400 |
| commit | dde1c652d7b1e69a3f1959697f039ad6dfaeb5dd (patch) | |
| tree | bf0d5cd0cdc609592862947b2872f4114bf669d5 /sound/core | |
| parent | b1974f965a506c131b60cd3e483340884e831920 (diff) | |
| download | linux-dde1c652d7b1e69a3f1959697f039ad6dfaeb5dd.tar.xz | |
ALSA: pcm: Fix false lockdep warnings
As PCM core handles the multiple linked streams in parallel, lockdep
gets confused (partly because of weak annotations) and spews the
false-positive warnings. This hasn't been a problem for long time but
the latest PCM lock path update seems to have woken up a sleeping
dog.
Here is an attempt to paper over this issue: pass the lock subclass
just calculated from the depth in snd_pcm_action_group(). Also, a
(possibly) wrong lock subclass set in snd_pcm_action_lock_mutex() is
dropped, too.
Reported-and-tested-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm_native.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 815396d8427f..166d59cdc86b 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -781,16 +781,15 @@ static int snd_pcm_action_group(struct action_ops *ops, { struct snd_pcm_substream *s = NULL; struct snd_pcm_substream *s1; - int res = 0; + int res = 0, depth = 1; snd_pcm_group_for_each_entry(s, substream) { if (do_lock && s != substream) { if (s->pcm->nonatomic) - mutex_lock_nested(&s->self_group.mutex, - SINGLE_DEPTH_NESTING); + mutex_lock_nested(&s->self_group.mutex, depth); else - spin_lock_nested(&s->self_group.lock, - SINGLE_DEPTH_NESTING); + spin_lock_nested(&s->self_group.lock, depth); + depth++; } res = ops->pre_action(s, state); if (res < 0) @@ -906,8 +905,7 @@ static int snd_pcm_action_lock_mutex(struct action_ops *ops, down_read(&snd_pcm_link_rwsem); if (snd_pcm_stream_linked(substream)) { mutex_lock(&substream->group->mutex); - mutex_lock_nested(&substream->self_group.mutex, - SINGLE_DEPTH_NESTING); + mutex_lock(&substream->self_group.mutex); res = snd_pcm_action_group(ops, substream, state, 1); mutex_unlock(&substream->self_group.mutex); mutex_unlock(&substream->group->mutex); |