[alsa-devel] [PATCH 2/3] Add ALSA driver for Atmel Audio Bitstream DAC

Takashi Iwai tiwai at suse.de
Wed Feb 4 13:52:06 CET 2009


At Wed, 4 Feb 2009 13:18:35 +0100,
Hans-Christian Egtvedt wrote:
> 
> > > +static int at32_abdac_trigger(struct snd_pcm_substream *substream,
> > > int cmd) +{
> > > +	struct at32_abdac *dac = snd_pcm_substream_chip(substream);
> > > +	int retval = -EINVAL;
> > > +
> > > +	switch (cmd) {
> > > +	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
> > > +	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
> > > +	case SNDRV_PCM_TRIGGER_START:
> > > +		clk_enable(dac->sample_clk);
> > > +		retval = dw_dma_cyclic_start(dac->dma.chan);
> > > +		if (retval)
> > > +			goto out;
> > > +		dac_writel(dac, CTRL, DAC_BIT(EN));
> > > +		break;
> > > +	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
> > > +	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
> > > +	case SNDRV_PCM_TRIGGER_STOP:
> > > +		set_bit(DMA_STOP, &dac->flags);
> > > +		dw_dma_cyclic_stop(dac->dma.chan);
> > > +		dac_writel(dac, DATA, 0);
> > > +		dac_writel(dac, CTRL, 0);
> > > +		clk_disable(dac->sample_clk);
> > > +		break;
> > 
> > No retval is set for these cases?
> > 
> 
> Nope, they are all void return functions and will always complete
> successfully.

I meant that retval is kept -EINVAL in the cases for STOP, etc,
although the call is successful.


Takashi


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