Hi Amadeusz, On 29-06-20, 11:05, Amadeusz Sławiński wrote: > > > On 6/29/2020 9:50 AM, Vinod Koul wrote: > > So we had some discussions of the stream states, so I thought it is a > > good idea to document the state transitions, so add it documentation > > > > Reviewed-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> > > --- > > .../sound/designs/compress-offload.rst | 51 +++++++++++++++++++ > > 1 file changed, 51 insertions(+) > > > > diff --git a/Documentation/sound/designs/compress-offload.rst b/Documentation/sound/designs/compress-offload.rst > > index ad4bfbdacc83..b6e9025ae105 100644 > > --- a/Documentation/sound/designs/compress-offload.rst > > +++ b/Documentation/sound/designs/compress-offload.rst > > @@ -151,6 +151,57 @@ Modifications include: > > - Addition of encoding options when required (derived from OpenMAX IL) > > - Addition of rateControlSupported (missing in OpenMAX AL) > > +State Machine > > +============= > > + > > +The compressed audio stream state machine is described below :: > > + > > + +----------+ > > + | | > > + | OPEN | > > + | | > > + +----------+ > > + | > > + | > > + | compr_set_params() > > + | > > + v > > + compr_free() +----------+ > > + +------------------------------------| | > > + | | SETUP | > > + | +------------------------>| |<-------------------------+ > > + | | compr_drain_notify() +----------+ | > > + | | or ^ | > > + | | compr_stop() | | > > + | | | compr_write() | > > + | | | | > > + | | | | Not sure, this is not in the version I posted, arrow is from setup -> prepare. See https://lore.kernel.org/alsa-devel/20200629075002.11436-2-vkoul@xxxxxxxxxx/ I don't know how it got reversed in your version, maybe the MUA messed up?? > > + | | +----------+ | > > + | | | | compr_free() | > > + | | | PREPARE |---------------> A | > > + | | | | | > > + | | +----------+ | > > + | | | | > > + | | | | > > + | | | compr_start() | > > + | | | | > > + | | v | > > + | +----------+ +----------+ | > > + | | | compr_drain() | | compr_stop() | > > + | | DRAIN |<-------------------| RUNNING |--------------------------+ > > + | | | | | | > > + | +----------+ +----------+ | > > + | | ^ | > > + | A | | | > > + | | compr_pause() | | compr_resume() | > > + | | | | | > > + | v v | | > > + | +----------+ +----------+ | > > + | | | | | compr_stop() | > > + +--->| FREE | | PAUSE |---------------------------+ > > + | | | | > > + +----------+ +----------+ > > + > > Gapless Playback > > ================ > > > > Line containing compr_free (between SETUP and FREE) seems to be misaligned? not in the version I posted and see on lore > If you move prepare to the left and drain in place of drain, it feels like > you won't need this weird indirection with A yeah that was a compromise to make it bit neater to me than adding overlapping arrows... > Something like: > > >> + v > > > + compr_free() +----------+ > > > + +------------------------------------| | > > > + | | SETUP | > > > + | +------------------------>| |<-------------------------+ > > > + | | compr_write() +----------+ | > > > + | | ^ | > > > + | | | compr_drain_notify() or | > > > + | | | compr_stop() | > > > + | | | | > > > + | | | | > > > + | | +----------+ | > > > + | | | | | > > > + | | | DRAIN | | > > > + | | | | | > > > + | | +----------+ | > > > + | | ^ | > > > + | | | | > > > + | | | compr_drain() | > > > + | | | | > > > + | | | | > > > + | +----------+ +----------+ | > > > + | | | compr_start() | | compr_stop() | > > > + | | PREPARE |------------------->| RUNNING |--------------------------+ > > > + | | | | | | > > > + | +----------+ +----------+ | > > > + | | | ^ | > > > + | | compr_free() | | | > > > + | | compr_pause() | | compr_resume() | > > > + | | | | | > > > + | v v | | > > > + | +----------+ +----------+ | > > > + | | | | | compr_stop() | > > > + +--->| FREE | | PAUSE |---------------------------+ > > > + | | | | > > > + +----------+ +----------+ > > > + > > but this makes me question PREPARE state, how do you enter it? a compr_write() moves from SETUP -> PREPARE. Fixing that above looks better version of mine.. -- ~Vinod
