Re: [alsa-devel] [PATCH] ASoC: snd_dmaengine: add common api forpcm_mmap

From: Lars-Peter Clausen
Date: Thu Jun 28 2012 - 08:26:35 EST


On 06/28/2012 02:18 PM, Mark Brown wrote:
> On Thu, Jun 28, 2012 at 02:15:38PM +0200, Takashi Iwai wrote:
>> Lars-Peter Clausen wrote:
>
>>> to the ALSA core. Now that there is a generic dma_mmap_writecombine it may
>>> make sense to integrate this with snd_pcm_lib_default_mmap.
>
>> Agreed.
>
>> Also, it must be portable. So far, only ARM has
>> dma_mmap_writecombine(), thus the build on other arch would fail as
>> is.
>
> Oh, dear - this means we don't actually have a generic API at all. Is
> there any effort being made to make this generally available?

Yes there is, and in fact in next/master there is generic
dma_mmap_writecombine. I'm not quite sure how it behaves on non ARM archs
though. But in theory it should fallback to a normal coherent mapping. Marek
did a lot of work on this, I've put him on Cc.

- Lars
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/