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, 4 insertions, 2 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 8e777f71717c..27284f628361 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -516,6 +516,7 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
                              struct snd_pcm_sw_params *params)
 {
         struct snd_pcm_runtime *runtime;
+        int err;
 
         if (PCM_RUNTIME_CHECK(substream))
                 return -ENXIO;
@@ -540,6 +541,7 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
                 if (params->silence_threshold > runtime->buffer_size)
                         return -EINVAL;
         }
+        err = 0;
         snd_pcm_stream_lock_irq(substream);
         runtime->tstamp_mode = params->tstamp_mode;
         runtime->period_step = params->period_step;
@@ -553,10 +555,10 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
                     runtime->silence_size > 0)
                         snd_pcm_playback_silence(substream, ULONG_MAX);
-                wake_up(&runtime->sleep);
+                err = snd_pcm_update_state(substream, runtime);
         }
         snd_pcm_stream_unlock_irq(substream);
-        return 0;
+        return err;
 }
 
 static int snd_pcm_sw_params_user(struct snd_pcm_substream *substream,