At Tue, 24 May 2011 12:15:05 +0800, Raymond Yau wrote:
As there is a 10 seconds schedule_timeout in alsa-kernel
The following error occur when aplay/arecord using a period time longer than 10 seconds for for those hda codec which support rate lower than 32000 when prealloc = 4096
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: