Re: [PATCH] ALSA: compress: allow to leave draining state when pausing in draining

From: Robert Lee
Date: Wed Jul 07 2021 - 22:23:13 EST


Hi Takashi,
Nice catch. I make a change and mail patch v2 for reviewing.

thanks,
Robert.


Takashi Iwai <tiwai@xxxxxxx> 於 2021年7月7日 週三 下午7:38寫道:
>
> On Tue, 06 Jul 2021 14:44:40 +0200,
> Robert Lee wrote:
> >
> > When compress offload pauses in draining state, not all platforms
> > need to keep in draining state. Some platforms may call drain or
> > partial drain again when resume from pause in draining, so it needs
> > to wake up from snd_compress_wait_for_drain() in this case.
> >
> > Call API snd_compr_leave_draining_in_pause(), if the platform
> > doesn't need to keep in draining state when pause in draining
> > state.
> >
> > Signed-off-by: Robert Lee <lerobert@xxxxxxxxxx>
>
> Well, the logic is a bit confusing (hard to understand what really
> "leave-draining-in-pause" actually means) but also error-prone;
> e.g. you left pause_in_draining flag set while changing the state to
> SNDRV_PCM_STATE_PAUSED. This will keep the pause_in_draining flag
> even after snd_compr_resume() call.
>
>
> thanks,
>
> Takashi
>
> > ---
> > include/sound/compress_driver.h | 14 ++++++++++++++
> > sound/core/compress_offload.c | 7 ++++++-
> > 2 files changed, 20 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
> > index 277087f635f3..e16524a93a14 100644
> > --- a/include/sound/compress_driver.h
> > +++ b/include/sound/compress_driver.h
> > @@ -145,6 +145,7 @@ struct snd_compr_ops {
> > * @lock: device lock
> > * @device: device id
> > * @use_pause_in_draining: allow pause in draining, true when set
> > + * @leave_draining_in_pause: leave draining state when pausing in draining
> > */
> > struct snd_compr {
> > const char *name;
> > @@ -156,6 +157,7 @@ struct snd_compr {
> > struct mutex lock;
> > int device;
> > bool use_pause_in_draining;
> > + bool leave_draining_in_pause;
> > #ifdef CONFIG_SND_VERBOSE_PROCFS
> > /* private: */
> > char id[64];
> > @@ -182,6 +184,18 @@ static inline void snd_compr_use_pause_in_draining(struct snd_compr_stream *subs
> > substream->device->use_pause_in_draining = true;
> > }
> >
> > +/**
> > + * snd_compr_leave_draining_in_pause - Leave draining state when pause in draining
> > + * @substream: compress substream to set
> > + *
> > + * In some platform, we need to leave draining state when we use pause in draining.
> > + * Add API to allow leave draining state.
> > + */
> > +static inline void snd_compr_leave_draining_in_pause(struct snd_compr_stream *substream)
> > +{
> > + substream->device->leave_draining_in_pause = true;
> > +}
> > +
> > /* dsp driver callback apis
> > * For playback: driver should call snd_compress_fragment_elapsed() to let the
> > * framework know that a fragment has been consumed from the ring buffer
> > diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> > index 21ce4c056a92..9c7bd4db6ecd 100644
> > --- a/sound/core/compress_offload.c
> > +++ b/sound/core/compress_offload.c
> > @@ -719,8 +719,13 @@ static int snd_compr_pause(struct snd_compr_stream *stream)
> > if (!stream->device->use_pause_in_draining)
> > return -EPERM;
> > retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
> > - if (!retval)
> > + if (!retval) {
> > stream->pause_in_draining = true;
> > + if (stream->device->leave_draining_in_pause) {
> > + stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
> > + wake_up(&stream->runtime->sleep);
> > + }
> > + }
> > break;
> > default:
> > return -EPERM;
> > --
> > 2.32.0.93.g670b81a890-goog
> >