On Tue, 29 Sep 2020 10:40:51 +0200, Gyeongtaek Lee wrote: > > On 9/29/20 04:13 PM, Takashi Iwai wrote: > >On Tue, 29 Sep 2020 03:51:35 +0200, > >Gyeongtaek Lee wrote: > >> > >> On 9/28/20 11:35 PM, Pierre-Louis Bossart wrote: > >> >On 9/28/20 6:13 AM, Jaroslav Kysela wrote: > >> >> Dne 28. 09. 20 v 12:50 Gyeongtaek Lee napsal(a): > >> >>> With a stream with low bitrate, user can't pause or resume the stream > >> >>> near the end of the stream because current ALSA doesn't allow it. > >> >>> If the stream has very low bitrate enough to store whole stream into > >> >>> the buffer, user can't do anything except stop the stream and then > >> >>> restart it from the first. > >> >>> If pause and resume is allowed during draining, user experience can be > >> >>> enhanced. > >> >> > >> >> It seems that we need a new state to handle the pause + drain condition for > >> >> this case. > >> >> > >> >> With this proposed change, the pause state in drain is invisible. > >> > > >> >Indeed it's be much nicer to have a new state, e..g > >> >SNDRV_PCM_STATE_DRAINING_PAUSED. > >> Ok. I will add the new state. > >> > > >> >One concern is that states are defined in uapi/sound/asoc.h, so wouldn't > >> >this have impacts on userspace as well? We'd change the value of > >> >SNDRV_PCM_STATE_LAST. > >> > > >> I also agree that adding new state and increase LAST value in the header of uapi > >> could be dangerous. So, I added it to comress_offload.h for now. > >> It could be merged into snd_pcm_state_t in someday with big changes. > >> Could you review the fixed patch below? > > > >Hrm, this resulted in rather more complex changes than the original > >patch. It shows that introducing yet another state is no good idea > >for this particular case. > > > >Since the possible application's behavior after this pause is as same > >as the normal pause (i.e. either resuming pause or dropping), I find > >it OK to take the original approach. > Thank you for the review. > I think that I should resend the original patch. Let's wait a bit for other opinions. We may add rather a new flag instead of introducing a new state, too, for example. Also, I'm not sure about any side-effect to drivers that expect the pause only during the running state. We might need some check for a capability flag? In anyway, the timing is bad; it's too late for 5.10 to apply such a core change. Can we postpone this for 5.11? thanks, Takashi > Am I right? > > > > > >thanks, > > > >Takashi > > > >> With a stream with low bitrate, user can't pause or resume the stream > >> near the end of the stream because current ALSA doesn't allow it. > >> If the stream has very low bitrate enough to store whole stream into > >> the buffer, user can't do anything except stop the stream and then > >> restart it from first. > >> If pause, resume are allowed during draining, user experience can be > >> enhanced. > >> > >> New state for pause during draining is defined in compress_offload.h for > >> now. If PCM_STATEs in uapi/sound/asound.h is changed, pcm libraries and > >> userspace application will be affected. > >> > >> Signed-off-by: Gyeongtaek Lee <gt82.lee@xxxxxxxxxxx> > >> Cc: stable@xxxxxxxxxxxxxxx > >> --- > >> include/uapi/sound/compress_offload.h | 3 ++ > >> sound/core/compress_offload.c | 47 ++++++++++++++++++++++----- > >> 2 files changed, 41 insertions(+), 9 deletions(-) > >> > >> diff --git a/include/uapi/sound/compress_offload.h b/include/uapi/sound/compress_offload.h > >> index 7184265c0b0d..f30b9851d1d7 100644 > >> --- a/include/uapi/sound/compress_offload.h > >> +++ b/include/uapi/sound/compress_offload.h > >> @@ -189,4 +189,7 @@ struct snd_compr_metadata { > >> #define SND_COMPR_TRIGGER_DRAIN 7 /*FIXME move this to pcm.h */ > >> #define SND_COMPR_TRIGGER_NEXT_TRACK 8 > >> #define SND_COMPR_TRIGGER_PARTIAL_DRAIN 9 > >> + > >> +/* FIXME move this to asound.h */ > >> +#define SNDRV_PCM_STATE_DRAINING_PAUSED (SNDRV_PCM_STATE_LAST + 1) > >> #endif > >> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c > >> index 0e53f6f31916..58fbe0d99431 100644 > >> --- a/sound/core/compress_offload.c > >> +++ b/sound/core/compress_offload.c > >> @@ -151,6 +151,7 @@ static int snd_compr_free(struct inode *inode, struct file *f) > >> case SNDRV_PCM_STATE_RUNNING: > >> case SNDRV_PCM_STATE_DRAINING: > >> case SNDRV_PCM_STATE_PAUSED: > >> + case SNDRV_PCM_STATE_DRAINING_PAUSED: > >> data->stream.ops->trigger(&data->stream, SNDRV_PCM_TRIGGER_STOP); > >> break; > >> default: > >> @@ -431,6 +432,7 @@ static __poll_t snd_compr_poll(struct file *f, poll_table *wait) > >> case SNDRV_PCM_STATE_RUNNING: > >> case SNDRV_PCM_STATE_PREPARED: > >> case SNDRV_PCM_STATE_PAUSED: > >> + case SNDRV_PCM_STATE_DRAINING_PAUSED: > >> if (avail >= stream->runtime->fragment_size) > >> retval = snd_compr_get_poll(stream); > >> break; > >> @@ -708,11 +710,23 @@ static int snd_compr_pause(struct snd_compr_stream *stream) > >> { > >> int retval; > >> > >> - if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING) > >> + switch (stream->runtime->state) { > >> + case SNDRV_PCM_STATE_RUNNING: > >> + retval = stream->ops->trigger(stream, > >> + SNDRV_PCM_TRIGGER_PAUSE_PUSH); > >> + if (!retval) > >> + stream->runtime->state = SNDRV_PCM_STATE_PAUSED; > >> + break; > >> + case SNDRV_PCM_STATE_DRAINING: > >> + retval = stream->ops->trigger(stream, > >> + SNDRV_PCM_TRIGGER_PAUSE_PUSH); > >> + if (!retval) > >> + stream->runtime->state = > >> + SNDRV_PCM_STATE_DRAINING_PAUSED; > >> + break; > >> + default: > >> return -EPERM; > >> - retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH); > >> - if (!retval) > >> - stream->runtime->state = SNDRV_PCM_STATE_PAUSED; > >> + } > >> return retval; > >> } > >> > >> @@ -720,11 +734,22 @@ static int snd_compr_resume(struct snd_compr_stream *stream) > >> { > >> int retval; > >> > >> - if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED) > >> + switch (stream->runtime->state) { > >> + case SNDRV_PCM_STATE_PAUSED: > >> + retval = stream->ops->trigger(stream, > >> + SNDRV_PCM_TRIGGER_PAUSE_RELEASE); > >> + if (!retval) > >> + stream->runtime->state = SNDRV_PCM_STATE_RUNNING; > >> + break; > >> + case SNDRV_PCM_STATE_DRAINING_PAUSED: > >> + retval = stream->ops->trigger(stream, > >> + SNDRV_PCM_TRIGGER_PAUSE_RELEASE); > >> + if (!retval) > >> + stream->runtime->state = SNDRV_PCM_STATE_DRAINING; > >> + break; > >> + default: > >> return -EPERM; > >> - retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE); > >> - if (!retval) > >> - stream->runtime->state = SNDRV_PCM_STATE_RUNNING; > >> + } > >> return retval; > >> } > >> > >> @@ -835,7 +860,9 @@ static int snd_compress_wait_for_drain(struct snd_compr_stream *stream) > >> */ > >> > >> ret = wait_event_interruptible(stream->runtime->sleep, > >> - (stream->runtime->state != SNDRV_PCM_STATE_DRAINING)); > >> + (stream->runtime->state != SNDRV_PCM_STATE_DRAINING) && > >> + (stream->runtime->state != > >> + SNDRV_PCM_STATE_DRAINING_PAUSED)); > >> if (ret == -ERESTARTSYS) > >> pr_debug("wait aborted by a signal\n"); > >> else if (ret) > >> @@ -857,6 +884,7 @@ static int snd_compr_drain(struct snd_compr_stream *stream) > >> case SNDRV_PCM_STATE_SETUP: > >> case SNDRV_PCM_STATE_PREPARED: > >> case SNDRV_PCM_STATE_PAUSED: > >> + case SNDRV_PCM_STATE_DRAINING_PAUSED: > >> return -EPERM; > >> case SNDRV_PCM_STATE_XRUN: > >> return -EPIPE; > >> @@ -909,6 +937,7 @@ static int snd_compr_partial_drain(struct snd_compr_stream *stream) > >> case SNDRV_PCM_STATE_SETUP: > >> case SNDRV_PCM_STATE_PREPARED: > >> case SNDRV_PCM_STATE_PAUSED: > >> + case SNDRV_PCM_STATE_DRAINING_PAUSED: > >> return -EPERM; > >> case SNDRV_PCM_STATE_XRUN: > >> return -EPIPE; > >> > >> base-commit: a1b8638ba1320e6684aa98233c15255eb803fac7 > >> -- > >> 2.21.0 > >> > >> > > >