I'm trying to fix brutefir to properly drain the driver before exiting.
This sequence does not work on a running stream. snd_pcm_nonblock()
removes the O_NONBLOCK flag from the file handle but the change does
not get copied to stream->f_flags. snd_pcm_drain() returns -EAGAIN
since the flags have not be copied.
snd_pcm_nonblock(handles[IO][n], 0);
snd_pcm_drain(handles[IO][n]);
snd_pcm_nonblock(handles[IO][n], SND_PCM_NONBLOCK);
static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream,
int state)
{
printk("snd_pcm_pre_drain_init flags %x\n", substream->f_flags);
if (substream->f_flags & O_NONBLOCK)
return -EAGAIN;
printk("snd_pcm_pre_drain_init 1\n");
substream->runtime->trigger_master = substream;
return 0;
}
Searching through the ALSA code the only way f_flags gets copied from
the file handle to the stream handle is via snd_pcm_prepare(). But I
can't do a snd_pcm_prepare() on a running stream. I can't find any way
to change the NONBLOCK status on a running stream.
I also tried implementing the wait for drain the the user app.
snd_pcm_drain() always returns -EAGAIN of O_NONBLOCK is set. It can't
be used to poll for the drain status.
So how do I wait for a stream to drain?
--
Jon Smirl
jonsmirl@xxxxxxxxx
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
