At Thu, 15 Nov 2007 14:28:14 -0600,
Timur Tabi wrote:
>
> Takashi Iwai wrote:
> > At Thu, 15 Nov 2007 09:00:54 -0600,
> > Timur Tabi wrote:
> >> Jaroslav Kysela wrote:
> >>
> >>> Yes, call snd_pcm_stop() function. The call must be protected with
> >>> snd_pcm_stream_lock... See to i2c/other/ak4117.c for an example.
> >> That code calls snd_pcm_stop() from a timer, not an ISR. Do I need the call to
> >> wake_up() as well?
> >
> > snd_pcm_stop() can be called from ISR, too (e.g.
> > snd_pcm_period_elapsed() may call snd_pcm_stop() when XRUN occurs).
> > You only need to protect it via snd_pcm_stream_lock*().
>
> It doesn't seem to do much. Here's the function I wrote:
>
> static void fsl_dma_abort_stream(struct snd_pcm_substream *substream)
> {
> unsigned long flags;
>
> snd_pcm_stream_lock_irqsave(substream, flags);
> if (snd_pcm_running(substream)) {
> snd_pcm_stop(substream, SNDRV_PCM_STATE_DRAINING);
You passed a wrong state. Usually snd_pcm_stop() passes either
SNDRV_PCM_STATE_SETUP (for post-draining) or SNDRV_PCM_STATE_XRUN (for
errors).
> wake_up(&substream->runtime->sleep);
> }
> snd_pcm_stream_unlock_irqrestore(substream, flags);
> }
This wake_up is superfluous. Now I understand your question in the
last mail...
> When I play a file, my DMA controller is incorrectly programmed (test case) and
> this function gets triggered. The application (aplay) does not terminate.
The app is *not* terminated, of course, but it must get an error when
it accesses to the PCM (-EPIPE in the case XRUN).
Takashi
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