From: Anna-Maria Gleixner anna-maria@linutronix.de

The snd_pcm_stream_lock_irq*() functions decouple disabling interrupts from the actual locking process. This does not work as expected if the locking primitives are replaced like on preempt-rt.

Provide one function for locking which uses correct locking primitives.

Signed-off-by: Anna-Maria Gleixner anna-maria@linutronix.de Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de --- sound/core/pcm_native.c | 85 +++++++++++++++++++++++++++-------------- 1 file changed, 57 insertions(+), 28 deletions(-)

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index d18b3982548b..92c10fc838e9 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -99,6 +99,57 @@ static inline void down_write_nonblock(struct rw_semaphore *lock) cond_resched(); }

+#define PCM_LOCK_DEFAULT 0 +#define PCM_LOCK_IRQ 1 +#define PCM_LOCK_IRQSAVE 2 + +static unsigned long __snd_pcm_stream_lock_mode(struct snd_pcm_substream *substream, + unsigned int mode) +{ + unsigned long flags = 0; + if (substream->pcm->nonatomic) { + down_read_nested(&snd_pcm_link_rwsem, SINGLE_DEPTH_NESTING); + mutex_lock(&substream->self_group.mutex); + } else { + switch (mode) { + case PCM_LOCK_DEFAULT: + read_lock(&snd_pcm_link_rwlock); + break; + case PCM_LOCK_IRQ: + read_lock_irq(&snd_pcm_link_rwlock); + break; + case PCM_LOCK_IRQSAVE: + read_lock_irqsave(&snd_pcm_link_rwlock, flags); + break; + } + spin_lock(&substream->self_group.lock); + } + return flags; +} + +static void __snd_pcm_stream_unlock_mode(struct snd_pcm_substream *substream, + unsigned int mode, unsigned long flags) +{ + if (substream->pcm->nonatomic) { + mutex_unlock(&substream->self_group.mutex); + up_read(&snd_pcm_link_rwsem); + } else { + spin_unlock(&substream->self_group.lock); + + switch (mode) { + case PCM_LOCK_DEFAULT: + read_unlock(&snd_pcm_link_rwlock); + break; + case PCM_LOCK_IRQ: + read_unlock_irq(&snd_pcm_link_rwlock); + break; + case PCM_LOCK_IRQSAVE: + read_unlock_irqrestore(&snd_pcm_link_rwlock, flags); + break; + } + } +} + /** * snd_pcm_stream_lock - Lock the PCM stream * @substream: PCM substream @@ -109,13 +160,7 @@ static inline void down_write_nonblock(struct rw_semaphore *lock) */ void snd_pcm_stream_lock(struct snd_pcm_substream *substream) { - if (substream->pcm->nonatomic) { - down_read_nested(&snd_pcm_link_rwsem, SINGLE_DEPTH_NESTING); - mutex_lock(&substream->self_group.mutex); - } else { - read_lock(&snd_pcm_link_rwlock); - spin_lock(&substream->self_group.lock); - } + __snd_pcm_stream_lock_mode(substream, PCM_LOCK_DEFAULT); } EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);

@@ -127,13 +172,7 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock); */ void snd_pcm_stream_unlock(struct snd_pcm_substream *substream) { - if (substream->pcm->nonatomic) { - mutex_unlock(&substream->self_group.mutex); - up_read(&snd_pcm_link_rwsem); - } else { - spin_unlock(&substream->self_group.lock); - read_unlock(&snd_pcm_link_rwlock); - } + __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_DEFAULT, 0); } EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);

@@ -147,9 +186,7 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock); */ void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream) { - if (!substream->pcm->nonatomic) - local_irq_disable(); - snd_pcm_stream_lock(substream); + __snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQ); } EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);

@@ -161,19 +198,13 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq); */ void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream) { - snd_pcm_stream_unlock(substream); - if (!substream->pcm->nonatomic) - local_irq_enable(); + __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQ, 0); } EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);

unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream) { - unsigned long flags = 0; - if (!substream->pcm->nonatomic) - local_irq_save(flags); - snd_pcm_stream_lock(substream); - return flags; + return __snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQSAVE); } EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);

@@ -187,9 +218,7 @@ EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave); void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream, unsigned long flags) { - snd_pcm_stream_unlock(substream); - if (!substream->pcm->nonatomic) - local_irq_restore(flags); + __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQSAVE, flags); } EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);