| Message ID | 20180702160454.6895-1-liam.r.girdwood@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 02 Jul 2018 18:10:44 +0200, Takashi Iwai wrote: > > On Mon, 02 Jul 2018 18:04:54 +0200, > Liam Girdwood wrote: > > > > 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> > > --- > > > > Changes since V1 :- > > > > o Remove API method and alow drivers to set directly. > > o Validate time is driver supplied times. > > > > include/sound/pcm.h | 1 + > > sound/core/pcm_lib.c | 10 ++++++++-- > > 2 files changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/include/sound/pcm.h b/include/sound/pcm.h > > index e054c583d3b3..edad4a506b93 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 -- */ > > diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c > > index 44b5ae833082..6909b896a6a1 100644 > > --- a/sound/core/pcm_lib.c > > +++ b/sound/core/pcm_lib.c > > @@ -1832,12 +1832,18 @@ static int wait_for_avail(struct snd_pcm_substream *substream, > > if (runtime->no_period_wakeup) > > wait_time = MAX_SCHEDULE_TIMEOUT; > > else { > > - wait_time = 10; > > + /* use wait time from substream if available */ > > + if (substream->wait_time) { > > + wait_time = substream->wait_time; > > + } else { > > + wait_time = 10 * 1000; /* 10 secs */ > > + } > > + > > This seems to be msec, but... > > > > if (runtime->rate) { > > long t = runtime->period_size * 2 / runtime->rate; > > wait_time = max(t, wait_time); > > ... here handled as a second. > > > } > > - wait_time = msecs_to_jiffies(wait_time * 1000); > > + wait_time = msecs_to_jiffies(wait_time); > > ... so this looks inconsistent. And I think we can forget runtime->rate check if it's specified explicitly. That is, something like: /* use wait time from substream if available */ if (substream->wait_time) { wait_time = substream->wait_time; } else { wait_time = 10; /* default 10 secs */ if (runtime->rate) { long t = runtime->period_size * 2 / runtime->rate; wait_time = max(t, wait_time); } wait_time *= 1000; } wait_time = msecs_to_jiffies(wait_time * 1000); Takashi
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index e054c583d3b3..edad4a506b93 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 -- */ diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 44b5ae833082..6909b896a6a1 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1832,12 +1832,18 @@ static int wait_for_avail(struct snd_pcm_substream *substream, if (runtime->no_period_wakeup) wait_time = MAX_SCHEDULE_TIMEOUT; else { - wait_time = 10; + /* use wait time from substream if available */ + if (substream->wait_time) { + wait_time = substream->wait_time; + } else { + wait_time = 10 * 1000; /* 10 secs */ + } + 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); } for (;;) {
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> --- Changes since V1 :- o Remove API method and alow drivers to set directly. o Validate time is driver supplied times. include/sound/pcm.h | 1 + sound/core/pcm_lib.c | 10 ++++++++-- 2 files changed, 9 insertions(+), 2 deletions(-)