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@opensource.cirrus.com Signed-off-by: Vinod Koul vkoul@kernel.org
.../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()|vcompr_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@kernel.org/
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:
vcompr_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..