From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: vkoul@kernel.org
Cc: perex@perex.cz, tiwai@suse.com, alsa-devel@alsa-project.org,
linux-kernel@vger.kernel.org, broonie@kernel.org,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: [RFC PATCH] ALSA: compress: Fix gapless playback state machine
Date: Wed, 10 Jun 2020 11:07:29 +0100 [thread overview]
Message-ID: <20200610100729.362-1-srinivas.kandagatla@linaro.org> (raw)
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:
1. set_params (Track 1), state = SNDRV_PCM_STATE_SETUP
2. set_metadata (Track 1), no state change, state = SNDRV_PCM_STATE_SETUP
3. fill and trigger start (Track 1), state = SNDRV_PCM_STATE_RUNNING
4. set_next_track (Track 2), state = SNDRV_PCM_STATE_RUNNING
5. 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
Fixes: f44f2a5417b2 ("ALSA: compress: fix drain calls blocking other compress functions (v6)")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
I wonder who did gapless work on upstream so far?
include/sound/compress_driver.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index 6ce8effa0b12..eabac33864c2 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -182,7 +182,7 @@ static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
if (snd_BUG_ON(!stream))
return;
- stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+ stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
wake_up(&stream->runtime->sleep);
}
--
2.21.0
next reply other threads:[~2020-06-10 10:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 10:07 Srinivas Kandagatla [this message]
2020-06-10 10:40 ` [RFC PATCH] ALSA: compress: Fix gapless playback state machine Jaroslav Kysela
2020-06-10 10:56 ` Srinivas Kandagatla
2020-06-10 10:58 ` Vinod Koul
2020-06-11 8:46 ` Charles Keepax
2020-06-11 9:09 ` Jaroslav Kysela
2020-06-11 9:44 ` Vinod Koul
2020-06-11 10:40 ` Jaroslav Kysela
2020-06-11 11:02 ` Vinod Koul
2020-06-11 10:42 ` Charles Keepax
2020-06-11 11:05 ` Vinod Koul
2020-06-10 12:56 ` Pierre-Louis Bossart
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200610100729.362-1-srinivas.kandagatla@linaro.org \
--to=srinivas.kandagatla@linaro.org \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=perex@perex.cz \
--cc=tiwai@suse.com \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).