This avoids bringing back the problem introduced by 62ba568f7aef ("ALSA: pcm: Return 0 when size < start_threshold in capture") and fixed in 00a399cad1a0 ("ALSA: pcm: Revert capture stream behavior change in blocking mode"), which prevented the user from starting capture from another thread.

Signed-off-by: Ricardo Biehl Pasquali pasqualirb@gmail.com --- sound/core/pcm_lib.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index bcb06bd3d..345ab1ab2 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -2176,6 +2176,10 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) snd_pcm_update_hw_ptr(substream);

+ /* + * If size < start_threshold, wait indefinitely. Another + * thread may start capture + */ if (!is_playback && runtime->status->state == SNDRV_PCM_STATE_PREPARED && size >= runtime->start_threshold) {