Currently ALSA core blocks userspace for about 10 seconds for PCM R/W IO. This needs to be configurable for modern hardware like DSPs where no pointer update in milliseconds can indicate terminal DSP errors.
Add a substream variable to set the wait time in ms. This allows userspace and drivers to recover more quickly from terminal DSP errors.
Signed-off-by: Liam Girdwood liam.r.girdwood@linux.intel.com --- include/sound/pcm.h | 6 ++++++ sound/core/pcm_lib.c | 15 ++++++++++----- 2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index e054c583d3b3..e4694684c524 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -462,6 +462,7 @@ struct snd_pcm_substream { /* -- timer section -- */ struct snd_timer *timer; /* timer */ unsigned timer_running: 1; /* time is running */ + unsigned wait_time; /* time in ms for R/W to wait for avail */ /* -- next substream -- */ struct snd_pcm_substream *next; /* -- linked substreams -- */ @@ -579,6 +580,11 @@ int snd_pcm_start(struct snd_pcm_substream *substream); int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t status); int snd_pcm_drain_done(struct snd_pcm_substream *substream); int snd_pcm_stop_xrun(struct snd_pcm_substream *substream); +static inline void snd_pcm_wait_time(struct snd_pcm_substream *substream, + unsigned wait_time) +{ + substream->wait_time = wait_time; +} #ifdef CONFIG_PM int snd_pcm_suspend(struct snd_pcm_substream *substream); int snd_pcm_suspend_all(struct snd_pcm *pcm); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index a83152e7d387..2ee76c70f55f 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1839,12 +1839,17 @@ static int wait_for_avail(struct snd_pcm_substream *substream, 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); + /* use wait time from substream if available */ + if (substream->wait_time) { + wait_time = msecs_to_jiffies(substream->wait_time); + } 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); } - wait_time = msecs_to_jiffies(wait_time * 1000); }
for (;;) {