[alsa-devel] [PATCH - JACK IO plug 2/2] jack: Update poll_fd also in draining state to support snd_pcm_drain

[Takashi Iwai]

On Tue, 03 Jul 2018 14:26:54 +0200,
<twischer at de.adit-jv.com> wrote:
> 
> From: Timo Wischer <twischer at de.adit-jv.com>
> 
> Signed-off-by: Timo Wischer <twischer at de.adit-jv.com>

Please give some change log text to explain why the patch is needed
and what it does.  The empty change log indicates already something
wrong unless it's a really trivial change.


thanks,

Takashi

> 
> diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c
> index 5a57e13..98a6f7e 100644
> --- a/jack/pcm_jack.c
> +++ b/jack/pcm_jack.c
> @@ -66,6 +66,7 @@ static int pcm_poll_block_check(snd_pcm_ioplug_t *io)
>  	snd_pcm_jack_t *jack = io->private_data;
>  
>  	if (io->state == SND_PCM_STATE_RUNNING ||
> +	    io->state == SND_PCM_STATE_DRAINING ||
>  	    (io->state == SND_PCM_STATE_PREPARED && io->stream == SND_PCM_STREAM_CAPTURE)) {
>  		avail = snd_pcm_ioplug_avail(io, jack->hw_ptr, io->appl_ptr);
>  		if (avail < jack->min_avail) {
> @@ -85,7 +86,12 @@ static int pcm_poll_unblock_check(snd_pcm_ioplug_t *io)
>  	snd_pcm_jack_t *jack = io->private_data;
>  
>  	avail = snd_pcm_ioplug_avail(io, jack->hw_ptr, io->appl_ptr);
> -	if (avail >= jack->min_avail) {
> +	/* In draining state poll_fd is used to wait
> +	 * till all pending frames are played.
> +	 * Therefore it has to be guarantee that a poll event is also generated
> +	 * if the buffer contains less than min_avail frames
> +	 */
> +	if (avail >= jack->min_avail || io->state == SND_PCM_STATE_DRAINING) {
>  		write(jack->fd, &buf, 1);
>  		return 1;
>  	}
> @@ -161,7 +167,8 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io)
>  		jack->areas[channel].step = jack->sample_bits;
>  	}
>  
> -	if (io->state == SND_PCM_STATE_RUNNING) {
> +	if (io->state == SND_PCM_STATE_RUNNING ||
> +	    io->state == SND_PCM_STATE_DRAINING) {
>  		snd_pcm_uframes_t hw_ptr = jack->hw_ptr;
>  		const snd_pcm_uframes_t hw_avail = snd_pcm_ioplug_hw_avail(io, hw_ptr,
>  									   io->appl_ptr);
> -- 
> 2.7.4
> 
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