Merge tag 'sound-4.20-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

[linux.git] / sound / core / pcm_native.c

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 66c90f486af913243a1005571a6c88cce93de76f..818dff1de545fad25669adf1144cbd49e5934067 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -36,6 +36,7 @@
 #include <sound/timer.h>
 #include <sound/minors.h>
 #include <linux/uio.h>
+#include <linux/delay.h>
 
 #include "pcm_local.h"
 
@@ -91,12 +92,12 @@ static DECLARE_RWSEM(snd_pcm_link_rwsem);
  * and this may lead to a deadlock when the code path takes read sem
  * twice (e.g. one in snd_pcm_action_nonatomic() and another in
  * snd_pcm_stream_lock()).  As a (suboptimal) workaround, let writer to
- * spin until it gets the lock.
+ * sleep until all the readers are completed without blocking by writer.
  */
-static inline void down_write_nonblock(struct rw_semaphore *lock)
+static inline void down_write_nonfifo(struct rw_semaphore *lock)
 {
        while (!down_write_trylock(lock))
-               cond_resched();
+               msleep(1);
 }
 
 #define PCM_LOCK_DEFAULT       0
@@ -1967,7 +1968,7 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
                res = -ENOMEM;
                goto _nolock;
        }
-       down_write_nonblock(&snd_pcm_link_rwsem);
+       down_write_nonfifo(&snd_pcm_link_rwsem);
        write_lock_irq(&snd_pcm_link_rwlock);
        if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN ||
            substream->runtime->status->state != substream1->runtime->status->state ||
@@ -2014,7 +2015,7 @@ static int snd_pcm_unlink(struct snd_pcm_substream *substream)
        struct snd_pcm_substream *s;
        int res = 0;
 
-       down_write_nonblock(&snd_pcm_link_rwsem);
+       down_write_nonfifo(&snd_pcm_link_rwsem);
        write_lock_irq(&snd_pcm_link_rwlock);
        if (!snd_pcm_stream_linked(substream)) {
                res = -EALREADY;
@@ -2369,7 +2370,8 @@ int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream)
 
 static void pcm_release_private(struct snd_pcm_substream *substream)
 {
-       snd_pcm_unlink(substream);
+       if (snd_pcm_stream_linked(substream))
+               snd_pcm_unlink(substream);
 }
 
 void snd_pcm_release_substream(struct snd_pcm_substream *substream)