Re: [PATCH] ALSA - HDA - Add period time constraint to hda-intel

[Takashi Iwai <tiwai@suse.de>]

At Thu, 26 May 2011 10:01:14 +0800,
Raymond Yau wrote:
> 
> 2011/5/24 Takashi Iwai <tiwai@suse.de>:
> 
> >> ALSA hda_intel.c:1680: azx_pcm_prepare: bufsize=0x1aeb00, format=0x4111
> >> ...
> >> ALSA pcm_native.c:1531: playback drain error (DMA or IRQ trouble?)
> >
> > Wouldn't it be better to fix the PCM timeout itself?
> > Does the patch below work?
> >
> >
> > thanks,
> >
> > Takashi
> >
> > ---
> > diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
> > index abfeff16..a754722 100644
> > --- a/sound/core/pcm_lib.c
> > +++ b/sound/core/pcm_lib.c
> > @@ -1756,8 +1756,16 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
> >        wait_queue_t wait;
> >        int err = 0;
> >        snd_pcm_uframes_t avail = 0;
> > +       long wait_time = 10; /* 10 seconds timeout as default */
> >        long tout;
> >
> > +       if (runtime->rate) {
> > +               long t = (runtime->period_size * 2 + runtime->rate - 1) /
> > +                       runtime->rate;
> > +               wait_time = max(t, wait_time);
> > +       }
> > +       wait_time = msecs_to_jiffies(wait_time * 1000);
> > +
> >        init_waitqueue_entry(&wait, current);
> >        add_wait_queue(&runtime->tsleep, &wait);
> >        for (;;) {
> > @@ -1767,7 +1775,7 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
> >                }
> >                set_current_state(TASK_INTERRUPTIBLE);
> >                snd_pcm_stream_unlock_irq(substream);
> > -               tout = schedule_timeout(msecs_to_jiffies(10000));
> > +               tout = schedule_timeout(wait_time);
> >                snd_pcm_stream_lock_irq(substream);
> >                switch (runtime->status->state) {
> >                case SNDRV_PCM_STATE_SUSPENDED:
> >
> 
> you patch only fix the playback write/capture read error .
> 
> does it mean that even when the application (e.g. PA server) set
> stop_threshold to boundary can only freerun for 10 seconds only ?

Yeah, this was overlooked.  The patch below fixes both issues.
Also it checks no_period_wakeup flag just to be sure (although setting
this for normal read/write/drain operations doesn't make sense).


thanks,

Takashi

---
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index abfeff16..f134130 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1756,8 +1756,18 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
 	wait_queue_t wait;
 	int err = 0;
 	snd_pcm_uframes_t avail = 0;
-	long tout;
-
+	long wait_time, tout;
+
+	if (runtime->no_period_wakeup)
+		wait_time = MAX_SCHEDULE_TIMEOUT;
+	else {
+		wait_time = 10;
+		if (runtime->rate) {
+			long t = runtime->period_size * 2 / runtime->rate;
+			wait_time = max(t, wait_time);
+		}
+		wait_time = msecs_to_jiffies(wait_time * 1000);
+	}
 	init_waitqueue_entry(&wait, current);
 	add_wait_queue(&runtime->tsleep, &wait);
 	for (;;) {
@@ -1765,9 +1775,8 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
 			err = -ERESTARTSYS;
 			break;
 		}
-		set_current_state(TASK_INTERRUPTIBLE);
 		snd_pcm_stream_unlock_irq(substream);
-		tout = schedule_timeout(msecs_to_jiffies(10000));
+		tout = schedule_timeout_interruptible(wait_time);
 		snd_pcm_stream_lock_irq(substream);
 		switch (runtime->status->state) {
 		case SNDRV_PCM_STATE_SUSPENDED:
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 1a07750..b597408 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1481,11 +1481,20 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 			break; /* all drained */
 		init_waitqueue_entry(&wait, current);
 		add_wait_queue(&to_check->sleep, &wait);
-		set_current_state(TASK_INTERRUPTIBLE);
 		snd_pcm_stream_unlock_irq(substream);
 		up_read(&snd_pcm_link_rwsem);
 		snd_power_unlock(card);
-		tout = schedule_timeout(10 * HZ);
+		if (runtime->no_period_wakeup)
+			tout = MAX_SCHEDULE_TIMEOUT;
+		else {
+			tout = 10;
+			if (runtime->rate) {
+				long t = runtime->period_size * 2 / runtime->rate;
+				tout = max(t, tout);
+			}
+			tout = msecs_to_jiffies(tout * 1000);
+		}
+		tout = schedule_timeout_interruptible(tout);
 		snd_power_lock(card);
 		down_read(&snd_pcm_link_rwsem);
 		snd_pcm_stream_lock_irq(substream);
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