Dne 11. 06. 20 v 10:46 Charles Keepax napsal(a):
On Wed, Jun 10, 2020 at 04:28:20PM +0530, Vinod Koul wrote:
On 10-06-20, 12:40, Jaroslav Kysela wrote:
Dne 10. 06. 20 v 12:07 Srinivas Kandagatla napsal(a):
For gapless playback call to snd_compr_drain_notify() after
partial drain should put the state to SNDRV_PCM_STATE_RUNNING
rather than SNDRV_PCM_STATE_SETUP as the driver is ready to
process the buffers for new track.
With existing code, if we are playing 3 tracks in gapless, after
partial drain finished on previous track 1 the state is set to
SNDRV_PCM_STATE_SETUP which is then moved to SNDRV_PCM_STATE_PREPARED
after data write. With this state calls to snd_compr_next_track() and
few other calls will fail as they expect the state to be in
SNDRV_PCM_STATE_RUNNING.
Here is the sequence of events and state transitions:
1. set_params (Track 1), state = SNDRV_PCM_STATE_SETUP
2. set_metadata (Track 1), no state change, state = SNDRV_PCM_STATE_SETUP
3. fill and trigger start (Track 1), state = SNDRV_PCM_STATE_RUNNING
4. set_next_track (Track 2), state = SNDRV_PCM_STATE_RUNNING
5. partial_drain (Track 1), state = SNDRV_PCM_STATE_SETUP
6 snd_compr_drain_notify (Track 1), state = SNDRV_PCM_STATE_SETUP
7. fill data (Track 2), state = SNDRV_PCM_STATE_PREPARED
8. set_metadata (Track 3), no state change, state = SNDRV_PCM_STATE_PREPARED
9. set_next_track (Track 3), !! FAILURE as state != SNDRV_PCM_STATE_RUNNING
The snd_compr_drain_notify() is called only from snd_compr_stop(). Something
is missing in this sequence?
It is supposed to be invoked by driver when partial drain is complete..
both intel and sprd driver are calling this. snd_compr_stop is stop
while draining case so legit
Not sure I follow this statement, could you elaborate a bit?
snd_compr_stop putting the state to RUNNING seems fundamentally
broken to me, the whole point of snd_compr_stop is to take the
state out of RUNNING.
Yes. I agree. It seems that the acknowledge for the partial drain should be
handled differently.
Jaroslav
Thanks,
Charles
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
