[PATCH 1/3] ALSA: compress: document the compress audio state machine

[Srinivas Kandagatla]

On 19/06/2020 05:54, 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
> 
> Signed-off-by: Vinod Koul <vkoul at kernel.org>
> ---

Thanks Vinod for doing this,
Makes things much clear on the state-machine side!

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla at linaro.org>

>   .../sound/designs/compress-offload.rst        | 52 +++++++++++++++++++
>   1 file changed, 52 insertions(+)
> 
> diff --git a/Documentation/sound/designs/compress-offload.rst b/Documentation/sound/designs/compress-offload.rst
> index ad4bfbdacc83..7292717c43bf 100644
> --- a/Documentation/sound/designs/compress-offload.rst
> +++ b/Documentation/sound/designs/compress-offload.rst
> @@ -151,6 +151,58 @@ 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_drain_notify()    |          |
> +              +------------------------>|   SETUP  |
> +              |                         |          |
> +              |                         +----------+
> +              |                              |
> +              |                              |
> +              |                              | compr_write()
> +              |                              |
> +              |                              V
> +              |                         +----------+
> +              |                         |          |
> +              |                         |  PREPARE |
> +              |                         |          |
> +              |                         +----------+
> +              |                              |
> +              |                              |
> +              |                              | compr_start()
> +              |                              |
> +              |                              V
> +        +----------+                    +----------+     compr_pause()      +----------+
> +        |          |                    |          |----------------------->|          |
> +        |  DRAIN   |<-------------------|  RUNNING |                        |  PAUSE   |
> +        |          |                    |          |<-----------------------|          |
> +        +----------+                    +----------+     compr_resume()     +----------+
> +              |                              |
> +              |                              |
> +              |                              | compr_free()
> +              |                              |
> +              |                              V
> +              |                         +----------+
> +              |     compr_free()        |          |
> +              +------------------------>|          |
> +                                        |   STOP   |
> +                                        |          |
> +                                        +----------+
> +
>   
>   Gapless Playback
>   ================
>