Thanks Russell and Vinod.

On Fri, May 25, 2012 at 4:05 PM, Russell King - ARM Linux <
linux@arm.linux.org.uk> wrote:

On Fri, May 25, 2012 at 01:23:36PM +0530, Vinod Koul wrote:

quoted

On Fri, 2012-05-25 at 15:11 +0800, Zhangfei Gao wrote:

quoted

mmp-pcm handle audio dma based on dmaengine
Support mmp and pxa910

Looks like this is *not* using soc-dmaengine library, why?

Note also...

Will look into soc-dmaengine.

quoted

quoted

+   prtd->dma_chan = dma_request_channel(mask, filter, prtd);
+   if (!prtd->dma_chan)
+           return -EINVAL;

This should be done at probe time, so we know the struct device, so
that...

Do you mean at open time, like snd_dmaengine_pcm_open.
The channel resource is limited and better get dynamically.
As a  result the pcm_new and preallocate already called before.

quoted

quoted

+static int mmp_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int

stream)

quoted

quoted

+{
+   struct snd_pcm_substream *substream =

pcm->streams[stream].substream;

quoted

quoted

+   struct snd_dma_buffer *buf = &substream->dma_buffer;
+   size_t size = mmp_pcm_hardware[stream].buffer_bytes_max;
+   struct gen_pool *gpool;
+
+   buf->dev.type = SNDRV_DMA_TYPE_DEV;
+   buf->dev.dev = pcm->card->dev;

... this uses the right device, and...

quoted

quoted

+static u64 mmp_pcm_dmamask = DMA_BIT_MASK(64);
+
+int mmp_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+   struct snd_card *card = rtd->card->snd_card;
+   struct snd_pcm *pcm = rtd->pcm;
+   int ret = 0;
+
+   if (!card->dev->dma_mask)
+           card->dev->dma_mask = &mmp_pcm_dmamask;
+
+   if (!card->dev->coherent_dma_mask)
+           card->dev->coherent_dma_mask = DMA_BIT_MASK(64);

... we don't need crap like this.

Because then we'll be allocating buffers against the _right_ struct device
which is the DMA engine struct device.
--
To unsubscribe from this list: send the line "unsubscribe alsa-devel" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

_______________________________________________
Alsa-devel mailing list
Alsa-devel at alsa-project.org
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20120525/af4b4fa0/attachment-0001.html>