Merge branch 'v4l_for_linus' of git://linuxtv.org/mchehab/for_linus

[pandora-kernel.git] / sound / core / pcm_lib.c

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 86d0caf..62e90b8 100644 (file)
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1761,6 +1761,10 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
        snd_pcm_uframes_t avail = 0;
        long wait_time, tout;
 
+       init_waitqueue_entry(&wait, current);
+       set_current_state(TASK_INTERRUPTIBLE);
+       add_wait_queue(&runtime->tsleep, &wait);
+
        if (runtime->no_period_wakeup)
                wait_time = MAX_SCHEDULE_TIMEOUT;
        else {
@@ -1771,16 +1775,32 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
                }
                wait_time = msecs_to_jiffies(wait_time * 1000);
        }
-       init_waitqueue_entry(&wait, current);
-       add_wait_queue(&runtime->tsleep, &wait);
+
        for (;;) {
                if (signal_pending(current)) {
                        err = -ERESTARTSYS;
                        break;
                }
+
+               /*
+                * We need to check if space became available already
+                * (and thus the wakeup happened already) first to close
+                * the race of space already having become available.
+                * This check must happen after been added to the waitqueue
+                * and having current state be INTERRUPTIBLE.
+                */
+               if (is_playback)
+                       avail = snd_pcm_playback_avail(runtime);
+               else
+                       avail = snd_pcm_capture_avail(runtime);
+               if (avail >= runtime->twake)
+                       break;
                snd_pcm_stream_unlock_irq(substream);
-               tout = schedule_timeout_interruptible(wait_time);
+
+               tout = schedule_timeout(wait_time);
+
                snd_pcm_stream_lock_irq(substream);
+               set_current_state(TASK_INTERRUPTIBLE);
                switch (runtime->status->state) {
                case SNDRV_PCM_STATE_SUSPENDED:
                        err = -ESTRPIPE;
@@ -1806,14 +1826,9 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
                        err = -EIO;
                        break;
                }
-               if (is_playback)
-                       avail = snd_pcm_playback_avail(runtime);
-               else
-                       avail = snd_pcm_capture_avail(runtime);
-               if (avail >= runtime->twake)
-                       break;
        }
  _endloop:
+       set_current_state(TASK_RUNNING);
        remove_wait_queue(&runtime->tsleep, &wait);
        *availp = avail;
        return err;