[PATCH 4.9 114/137] ALSA: compress: Fix stop handling on compressed capture streams

From: Greg Kroah-Hartman
Date: Mon Feb 11 2019 - 10:10:41 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

commit 4f2ab5e1d13d6aa77c55f4914659784efd776eb4 upstream.

It is normal user behaviour to start, stop, then start a stream
again without closing it. Currently this works for compressed
playback streams but not capture ones.

The states on a compressed capture stream go directly from OPEN to
PREPARED, unlike a playback stream which moves to SETUP and waits
for a write of data before moving to PREPARED. Currently however,
when a stop is sent the state is set to SETUP for both types of
streams. This leaves a capture stream in the situation where a new
start can't be sent as that requires the state to be PREPARED and
a new set_params can't be sent as that requires the state to be
OPEN. The only option being to close the stream, and then reopen.

Correct this issues by allowing snd_compr_drain_notify to set the
state depending on the stream direction, as we already do in

Fixes: 49bb6402f1aa ("ALSA: compress_core: Add support for capture streams")
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

include/sound/compress_driver.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -185,7 +185,11 @@ static inline void snd_compr_drain_notif
if (snd_BUG_ON(!stream))

- stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+ if (stream->direction == SND_COMPRESS_PLAYBACK)
+ stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+ else
+ stream->runtime->state = SNDRV_PCM_STATE_PREPARED;