ALSA: pcm_core: Fix wake_up() optimization

This change fixes the "ALSA: pcm_lib - optimize wake_up() calls for PCM I/O"
commit. New sleeping queue is introduced to separate user space and kernel
space wake_ups. runtime->nowake is renamed to twake (transfer wake).

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

3 files changed, 14 insertions, 10 deletions

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index df57a0e30bf2..0d428d0896db 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -894,6 +894,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
         memset((void*)runtime->control, 0, size);
 
         init_waitqueue_head(&runtime->sleep);
+        init_waitqueue_head(&runtime->tsleep);
 
         runtime->status->state = SNDRV_PCM_STATE_OPEN;
 
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 5417f7dce834..e2a817eac2a9 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -285,8 +285,8 @@ int snd_pcm_update_state(struct snd_pcm_substream *substream,
                         return -EPIPE;
                 }
         }
-        if (!runtime->nowake && avail >= runtime->control->avail_min)
-                wake_up(&runtime->sleep);
+        if (avail >= runtime->control->avail_min)
+                wake_up(runtime->twake ? &runtime->tsleep : &runtime->sleep);
         return 0;
 }
 
@@ -1692,7 +1692,7 @@ static int wait_for_avail_min(struct snd_pcm_substream *substream,
         long tout;
 
         init_waitqueue_entry(&wait, current);
-        add_wait_queue(&runtime->sleep, &wait);
+        add_wait_queue(&runtime->tsleep, &wait);
         for (;;) {
                 if (signal_pending(current)) {
                         err = -ERESTARTSYS;
@@ -1735,7 +1735,7 @@ static int wait_for_avail_min(struct snd_pcm_substream *substream,
                         break;
         }
  _endloop:
-        remove_wait_queue(&runtime->sleep, &wait);
+        remove_wait_queue(&runtime->tsleep, &wait);
         *availp = avail;
         return err;
 }
@@ -1794,7 +1794,7 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
                 goto _end_unlock;
         }
 
-        runtime->nowake = 1;
+        runtime->twake = 1;
         while (size > 0) {
                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
                 snd_pcm_uframes_t avail;
@@ -1816,7 +1816,7 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
                 if (frames > cont)
                         frames = cont;
                 if (snd_BUG_ON(!frames)) {
-                        runtime->nowake = 0;
+                        runtime->twake = 0;
                         snd_pcm_stream_unlock_irq(substream);
                         return -EINVAL;
                 }
@@ -1855,7 +1855,7 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
                 }
         }
  _end_unlock:
-        runtime->nowake = 0;
+        runtime->twake = 0;
         if (xfer > 0 && err >= 0)
                 snd_pcm_update_state(substream, runtime);
         snd_pcm_stream_unlock_irq(substream);
@@ -2016,7 +2016,7 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
                 goto _end_unlock;
         }
 
-        runtime->nowake = 1;
+        runtime->twake = 1;
         while (size > 0) {
                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
                 snd_pcm_uframes_t avail;
@@ -2045,7 +2045,7 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
                 if (frames > cont)
                         frames = cont;
                 if (snd_BUG_ON(!frames)) {
-                        runtime->nowake = 0;
+                        runtime->twake = 0;
                         snd_pcm_stream_unlock_irq(substream);
                         return -EINVAL;
                 }
@@ -2078,7 +2078,7 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
                 xfer += frames;
         }
  _end_unlock:
-        runtime->nowake = 0;
+        runtime->twake = 0;
         if (xfer > 0 && err >= 0)
                 snd_pcm_update_state(substream, runtime);
         snd_pcm_stream_unlock_irq(substream);
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 27284f628361..56ec35e8510b 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -919,6 +919,7 @@ static void snd_pcm_post_stop(struct snd_pcm_substream *substream, int state)
                 runtime->status->state = state;
         }
         wake_up(&runtime->sleep);
+        wake_up(&runtime->tsleep);
 }
 
 static struct action_ops snd_pcm_action_stop = {
@@ -1004,6 +1005,7 @@ static void snd_pcm_post_pause(struct snd_pcm_substream *substream, int push)
                                          SNDRV_TIMER_EVENT_MPAUSE,
                                          &runtime->trigger_tstamp);
                 wake_up(&runtime->sleep);
+                wake_up(&runtime->tsleep);
         } else {
                 runtime->status->state = SNDRV_PCM_STATE_RUNNING;
                 if (substream->timer)
@@ -1061,6 +1063,7 @@ static void snd_pcm_post_suspend(struct snd_pcm_substream *substream, int state)
         runtime->status->suspended_state = runtime->status->state;
         runtime->status->state = SNDRV_PCM_STATE_SUSPENDED;
         wake_up(&runtime->sleep);
+        wake_up(&runtime->tsleep);
 }
 
 static struct action_ops snd_pcm_action_suspend = {