ALSA: pcm_lib - optimize wake_up() calls for PCM I/O

As noted by pl bossart <bossart.nospam@gmail.com>, the PCM I/O routines
(snd_pcm_lib_write1, snd_pcm_lib_read1) should block wake_up() calls
until all samples are not processed.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index fe1b131842be..e26fb3c58037 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -311,6 +311,7 @@ struct snd_pcm_runtime {
         struct snd_pcm_mmap_control *control;
 
         /* -- locking / scheduling -- */
+        unsigned int nowake: 1;         /* no wakeup (data-copy in progress) */
         wait_queue_head_t sleep;
         struct fasync_struct *fasync;
 
@@ -839,6 +840,8 @@ void snd_pcm_set_sync(struct snd_pcm_substream *substream);
 int snd_pcm_lib_interleave_len(struct snd_pcm_substream *substream);
 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
                       unsigned int cmd, void *arg);                      
+int snd_pcm_update_state(struct snd_pcm_substream *substream,
+                         struct snd_pcm_runtime *runtime);
 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
 int snd_pcm_playback_xrun_check(struct snd_pcm_substream *substream);
 int snd_pcm_capture_xrun_check(struct snd_pcm_substream *substream);