@@ -617,6 +617,7 @@ void snd_pcm_stream_unlock(struct snd_pcm_substream *substream);
void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream);
void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream);
unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream);
+unsigned long _snd_pcm_stream_lock_irqsave_nested(struct snd_pcm_substream *substream);
/**
* snd_pcm_stream_lock_irqsave - Lock the PCM stream
@@ -635,6 +636,20 @@ unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream);
void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
unsigned long flags);
+/**
+ * snd_pcm_stream_lock_irqsave_nested - Single-nested PCM stream locking
+ * @substream: PCM substream
+ * @flags: irq flags
+ *
+ * This locks the PCM stream like snd_pcm_stream_lock_irqsave() but with
+ * the single-depth lockdep subclass.
+ */
+#define snd_pcm_stream_lock_irqsave_nested(substream, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = _snd_pcm_stream_lock_irqsave_nested(substream); \
+ } while (0)
+
/**
* snd_pcm_group_for_each_entry - iterate over the linked substreams
* @s: the iterator
@@ -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
@@ -46,8 +46,8 @@ static inline void snd_soc_dpcm_stream_lock_irq(struct snd_soc_pcm_runtime *rtd,
snd_pcm_stream_lock_irq(snd_soc_dpcm_get_substream(rtd, stream));
}
-#define snd_soc_dpcm_stream_lock_irqsave(rtd, stream, flags) \
- snd_pcm_stream_lock_irqsave(snd_soc_dpcm_get_substream(rtd, stream), flags)
+#define snd_soc_dpcm_stream_lock_irqsave_nested(rtd, stream, flags) \
+ snd_pcm_stream_lock_irqsave_nested(snd_soc_dpcm_get_substream(rtd, stream), flags)
static inline void snd_soc_dpcm_stream_unlock_irq(struct snd_soc_pcm_runtime *rtd,
int stream)
@@ -2094,7 +2094,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
be = dpcm->be;
be_substream = snd_soc_dpcm_get_substream(be, stream);
- snd_soc_dpcm_stream_lock_irqsave(be, stream, flags);
+ snd_soc_dpcm_stream_lock_irqsave_nested(be, stream, flags);
/* is this op for this BE ? */
if (!snd_soc_dpcm_be_can_update(fe, be, stream))
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 <hdegoede@redhat.com> Reported-and-tested-by: Marek Szyprowski <m.szyprowski@samsung.com> 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 <tiwai@suse.de> --- v1->v2: Correct Fixes tag, a typo fix include/sound/pcm.h | 15 +++++++++++++++ sound/core/pcm_native.c | 13 +++++++++++++ sound/soc/soc-pcm.c | 6 +++--- 3 files changed, 31 insertions(+), 3 deletions(-)