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

From: Srinivas Kandagatla
Date: Fri Jun 19 2020 - 05:29:42 EST




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@xxxxxxxxxx>
---

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

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

.../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
================