From 3c75c0ea5da749bd1efebd1387f2e5011b8c7d78 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 19 Jan 2022 16:52:48 +0100 Subject: ASoC: soc-pcm: Fix DPCM lockdep warning due to nested stream locks The recent change for DPCM locking caused spurious lockdep warnings. Actually the warnings are false-positive, as those are triggered due to the nested stream locks for FE and BE. Since both locks belong to the same lock class, lockdep sees it as if a deadlock. For fixing this, we need to take PCM stream locks for BE with the nested lock primitives. Since currently snd_pcm_stream_lock*() helper assumes only the top-level single locking, a new helper function snd_pcm_stream_lock_irqsave_nested() is defined for a single-depth nested lock, which is now used in the BE DAI trigger that is always performed inside a FE stream lock. Fixes: b2ae80663008 ("ASoC: soc-pcm: serialize BE triggers") Reported-and-tested-by: Hans de Goede Reported-and-tested-by: Marek Szyprowski Link: https://lore.kernel.org/r/73018f3c-9769-72ea-0325-b3f8e2381e30@redhat.com Link: https://lore.kernel.org/alsa-devel/9a0abddd-49e9-872d-2f00-a1697340f786@samsung.com Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20220119155249.26754-2-tiwai@suse.de Signed-off-by: Mark Brown --- sound/core/pcm_native.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'sound/core/pcm_native.c') diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 621883e71194..a056b3ef3c84 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -172,6 +172,19 @@ unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream) } EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave); +unsigned long _snd_pcm_stream_lock_irqsave_nested(struct snd_pcm_substream *substream) +{ + unsigned long flags = 0; + if (substream->pcm->nonatomic) + mutex_lock_nested(&substream->self_group.mutex, + SINGLE_DEPTH_NESTING); + else + spin_lock_irqsave_nested(&substream->self_group.lock, flags, + SINGLE_DEPTH_NESTING); + return flags; +} +EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave_nested); + /** * snd_pcm_stream_unlock_irqrestore - Unlock the PCM stream * @substream: PCM substream -- cgit