ALSA: pcm - Fix drain behavior in non-blocking mode
The current PCM core has the following problems regarding PCM draining
in non-blocking mode:
- the current f_flags isn't checked in snd_pcm_drain(), thus changing
the mode dynamically via snd_pcm_nonblock() after open doesn't work.
- calling drain in non-blocking mode just return -EAGAIN error, but
doesn't provide any way to sync with draining.
This patch fixes these issues.
- check file->f_flags in snd_pcm_drain() properly
- when O_NONBLOCK is set, PCM core sets the stream(s) to DRAIN state
but quits ioctl immediately without waiting the whole drain; the
caller can sync the drain manually via poll()
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 72cfd47..e3e78c7 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -197,12 +197,16 @@
avail = snd_pcm_capture_avail(runtime);
if (avail > runtime->avail_max)
runtime->avail_max = avail;
- if (avail >= runtime->stop_threshold) {
- if (substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING)
+ if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
+ if (avail >= runtime->buffer_size) {
snd_pcm_drain_done(substream);
- else
+ return -EPIPE;
+ }
+ } else {
+ if (avail >= runtime->stop_threshold) {
xrun(substream);
- return -EPIPE;
+ return -EPIPE;
+ }
}
if (avail >= runtime->control->avail_min)
wake_up(&runtime->sleep);