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:
- set_params (Track 1), state = SNDRV_PCM_STATE_SETUP
- set_metadata (Track 1), no state change, state = SNDRV_PCM_STATE_SETUP
- fill and trigger start (Track 1), state = SNDRV_PCM_STATE_RUNNING
- set_next_track (Track 2), state = SNDRV_PCM_STATE_RUNNING
- 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
Somehow not sure how it got missed earlier, but this seem a decent fix but we still need to check all the states here..