Re: [PATCH V2 01/10] ASoc: mxs: add mxs-pcm driver

[Dong Aisheng-B29396 <B29396@freescale.com>]

> -----Original Message-----
> From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
> Sent: Wednesday, July 13, 2011 7:27 AM
> To: Dong Aisheng-B29396
> Cc: alsa-devel@alsa-project.org; linux-arm-kernel@lists.infradead.org;
> lrg@ti.com; s.hauer@pengutronix.de; u.kleine-koenig@pengutronix.de
> Subject: Re: [PATCH V2 01/10] ASoc: mxs: add mxs-pcm driver
> 
> On Tue, Jul 12, 2011 at 11:04:36PM +0800, Dong Aisheng wrote:
> 
> > +	if (dai->driver->capture.channels_min) {
> > +		ret = mxs_pcm_preallocate_dma_buffer(pcm,
> > +			SNDRV_PCM_STREAM_CAPTURE);
> > +		if (ret)
> > +			goto out;
> > +	}
> 
> For robustness replace the channels_min check with a check for the
> relevant substream being present (see pxa2xx-pcm.c for a recent example).
Is this change ok?
diff --git a/sound/soc/mxs/mxs-pcm.c b/sound/soc/mxs/mxs-pcm.c
index 3e3a8c8..a385ba9 100644
--- a/sound/soc/mxs/mxs-pcm.c
+++ b/sound/soc/mxs/mxs-pcm.c
@@ -288,14 +288,14 @@ static int mxs_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
                card->dev->dma_mask = &mxs_pcm_dmamask;
        if (!card->dev->coherent_dma_mask)
                card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
-       if (dai->driver->playback.channels_min) {
+       if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
                ret = mxs_pcm_preallocate_dma_buffer(pcm,
                        SNDRV_PCM_STREAM_PLAYBACK);
                if (ret)
                        goto out;
        }

-       if (dai->driver->capture.channels_min) {
+       if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
                ret = mxs_pcm_preallocate_dma_buffer(pcm,
                        SNDRV_PCM_STREAM_CAPTURE);
                if (ret)

Regards
Dong Aisheng