[alsa-devel] [PATCH 1/4] ALSA: compress: Fix regression on compressed capture streams
A previous fix to the stop handling on compressed capture streams causes some knock on issues. The previous fix updated snd_compr_drain_notify to set the state back to PREPARED for capture streams. This causes some issues however as the handling for snd_compr_poll differs between the two states and some user-space applications were relying on the poll failing after the stream had been stopped.
To correct this regression whilst still fixing the original problem the patch was addressing, update the capture handling to skip the PREPARED state rather than skipping the SETUP state as it has done until now.
Fixes: 4f2ab5e1d13d ("ALSA: compress: Fix stop handling on compressed capture streams") Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com --- include/sound/compress_driver.h | 5 +---- sound/core/compress_offload.c | 16 +++++++++++----- 2 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h index c5188ff724d12..bc88d6f964da9 100644 --- a/include/sound/compress_driver.h +++ b/include/sound/compress_driver.h @@ -173,10 +173,7 @@ static inline void snd_compr_drain_notify(struct snd_compr_stream *stream) if (snd_BUG_ON(!stream)) return;
- if (stream->direction == SND_COMPRESS_PLAYBACK) - stream->runtime->state = SNDRV_PCM_STATE_SETUP; - else - stream->runtime->state = SNDRV_PCM_STATE_PREPARED; + stream->runtime->state = SNDRV_PCM_STATE_SETUP;
wake_up(&stream->runtime->sleep); } diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index a1a6fd75cfe50..f031495311ee4 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -587,10 +587,7 @@ snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg) stream->metadata_set = false; stream->next_track = false;
- if (stream->direction == SND_COMPRESS_PLAYBACK) - stream->runtime->state = SNDRV_PCM_STATE_SETUP; - else - stream->runtime->state = SNDRV_PCM_STATE_PREPARED; + stream->runtime->state = SNDRV_PCM_STATE_SETUP; } else { return -EPERM; } @@ -706,8 +703,17 @@ static int snd_compr_start(struct snd_compr_stream *stream) { int retval;
- if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED) + switch (stream->runtime->state) { + case SNDRV_PCM_STATE_SETUP: + if (stream->direction != SND_COMPRESS_CAPTURE) + return -EPERM; + break; + case SNDRV_PCM_STATE_PREPARED: + break; + default: return -EPERM; + } + retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START); if (!retval) stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
Currently, whilst in SNDRV_PCM_STATE_OPEN it is possible to call snd_compr_stop, snd_compr_drain and snd_compr_partial_drain, which allow a transition to SNDRV_PCM_STATE_SETUP. The stream should only be able to move to the setup state once it has received a SNDRV_COMPRESS_SET_PARAMS ioctl. Fix this issue by not allowing those ioctls whilst in the open state.
Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com --- sound/core/compress_offload.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index f031495311ee4..e1a216fd832f9 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -724,9 +724,15 @@ static int snd_compr_stop(struct snd_compr_stream *stream) { int retval;
- if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED || - stream->runtime->state == SNDRV_PCM_STATE_SETUP) + switch (stream->runtime->state) { + case SNDRV_PCM_STATE_OPEN: + case SNDRV_PCM_STATE_SETUP: + case SNDRV_PCM_STATE_PREPARED: return -EPERM; + default: + break; + } + retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP); if (!retval) { snd_compr_drain_notify(stream); @@ -814,9 +820,14 @@ static int snd_compr_drain(struct snd_compr_stream *stream) { int retval;
- if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED || - stream->runtime->state == SNDRV_PCM_STATE_SETUP) + switch (stream->runtime->state) { + case SNDRV_PCM_STATE_OPEN: + case SNDRV_PCM_STATE_SETUP: + case SNDRV_PCM_STATE_PREPARED: return -EPERM; + default: + break; + }
retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN); if (retval) { @@ -853,9 +864,16 @@ static int snd_compr_next_track(struct snd_compr_stream *stream) static int snd_compr_partial_drain(struct snd_compr_stream *stream) { int retval; - if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED || - stream->runtime->state == SNDRV_PCM_STATE_SETUP) + + switch (stream->runtime->state) { + case SNDRV_PCM_STATE_OPEN: + case SNDRV_PCM_STATE_SETUP: + case SNDRV_PCM_STATE_PREPARED: return -EPERM; + default: + break; + } + /* stream can be drained only when next track has been signalled */ if (stream->next_track == false) return -EPERM;
Partial drain and next track are intended for gapless playback and don't really have an obvious interpretation for a capture stream, so makes sense to not allow those operations on capture streams. Drain would make sense on a capture stream but currently the implementation of drain involves the kernel waiting for the DSP to consume its available data, whereas a capture drain would involve waiting for user-space to consume the data available on the DSP. Disallow drain on capture streams until that is implemented.
Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com --- sound/core/compress_offload.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index e1a216fd832f9..c7d56cee0d510 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -829,6 +829,10 @@ static int snd_compr_drain(struct snd_compr_stream *stream) break; }
+ /* drain not implemented for capture streams yet */ + if (stream->direction == SND_COMPRESS_CAPTURE) + return -EPERM; + retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN); if (retval) { pr_debug("SND_COMPR_TRIGGER_DRAIN failed %d\n", retval); @@ -847,6 +851,10 @@ static int snd_compr_next_track(struct snd_compr_stream *stream) if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING) return -EPERM;
+ /* next track doesn't have any meaning for capture streams */ + if (stream->direction == SND_COMPRESS_CAPTURE) + return -EPERM; + /* you can signal next track if this is intended to be a gapless stream * and current track metadata is set */ @@ -874,6 +882,10 @@ static int snd_compr_partial_drain(struct snd_compr_stream *stream) break; }
+ /* partial drain doesn't have any meaning for capture streams */ + if (stream->direction == SND_COMPRESS_CAPTURE) + return -EPERM; + /* stream can be drained only when next track has been signalled */ if (stream->next_track == false) return -EPERM;
On 09-07-19, 11:52, Charles Keepax wrote:
Partial drain and next track are intended for gapless playback and don't really have an obvious interpretation for a capture stream, so makes sense to not allow those operations on capture streams. Drain
Sounds right
would make sense on a capture stream but currently the implementation of drain involves the kernel waiting for the DSP to consume its available data, whereas a capture drain would involve waiting for user-space to consume the data available on the DSP. Disallow drain on capture streams until that is implemented.
Well it in unclear to me about the support required in kernel! Kernel issues drain request to DSP and waits for that to be done. When DSP has encoded and copied the data the notification should make drain complete. So I dont see anything in kernel required for that
Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com
sound/core/compress_offload.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index e1a216fd832f9..c7d56cee0d510 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -829,6 +829,10 @@ static int snd_compr_drain(struct snd_compr_stream *stream) break; }
- /* drain not implemented for capture streams yet */
- if (stream->direction == SND_COMPRESS_CAPTURE)
return -EPERM;- retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN); if (retval) { pr_debug("SND_COMPR_TRIGGER_DRAIN failed %d\n", retval);
@@ -847,6 +851,10 @@ static int snd_compr_next_track(struct snd_compr_stream *stream) if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING) return -EPERM;
- /* next track doesn't have any meaning for capture streams */
- if (stream->direction == SND_COMPRESS_CAPTURE)
return -EPERM;- /* you can signal next track if this is intended to be a gapless stream
*/
- and current track metadata is set
@@ -874,6 +882,10 @@ static int snd_compr_partial_drain(struct snd_compr_stream *stream) break; }
- /* partial drain doesn't have any meaning for capture streams */
- if (stream->direction == SND_COMPRESS_CAPTURE)
return -EPERM;- /* stream can be drained only when next track has been signalled */ if (stream->next_track == false) return -EPERM;
-- 2.11.0
On Tue, Jul 09, 2019 at 05:06:33PM +0530, Vinod Koul wrote:
On 09-07-19, 11:52, Charles Keepax wrote:
would make sense on a capture stream but currently the implementation of drain involves the kernel waiting for the DSP to consume its available data, whereas a capture drain would involve waiting for user-space to consume the data available on the DSP. Disallow drain on capture streams until that is implemented.
Well it in unclear to me about the support required in kernel! Kernel issues drain request to DSP and waits for that to be done. When DSP has encoded and copied the data the notification should make drain complete. So I dont see anything in kernel required for that
Ok that makes sense I think what I missed there is we are looking at the capture drain being complete when the data is in the DSP buffer, not when it has been pulled by user-space as I had.
I will update the patch to remove this one.
Thanks, Charles
Draining makes little sense in the situation of hardware overrun, as the hardware will have consumed all its available samples. Additionally, draining whilst the stream is paused would presumably get stuck as no data is being consumed on the DSP side.
Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com --- sound/core/compress_offload.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index c7d56cee0d510..9fcd06395a046 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -824,7 +824,10 @@ static int snd_compr_drain(struct snd_compr_stream *stream) case SNDRV_PCM_STATE_OPEN: case SNDRV_PCM_STATE_SETUP: case SNDRV_PCM_STATE_PREPARED: + case SNDRV_PCM_STATE_PAUSED: return -EPERM; + case SNDRV_PCM_STATE_XRUN: + return -EPIPE; default: break; } @@ -877,7 +880,10 @@ static int snd_compr_partial_drain(struct snd_compr_stream *stream) case SNDRV_PCM_STATE_OPEN: case SNDRV_PCM_STATE_SETUP: case SNDRV_PCM_STATE_PREPARED: + case SNDRV_PCM_STATE_PAUSED: return -EPERM; + case SNDRV_PCM_STATE_XRUN: + return -EPIPE; default: break; }
participants (2)
-
Charles Keepax -
Vinod Koul