At Tue, 26 Aug 2008 15:01:18 -0600,
Grant Grundler wrote:
> On Tue, Aug 26, 2008 at 05:25:24PM +0200, Takashi Iwai wrote:
> > Now updated my git tree:
> > http://git.kernel.org/?p=linux/kernel/git/tiwai/sound-2.6.git;a=shortlog;h=topic/dma-fix
> > I'll post each patch again if preferred.
> +#ifdef CONFIG_SND_COHERENT_DMA
> #define SNDRV_DMA_TYPE_DEV_SG 3 /* generic device SG-buffer */
> +#define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */
> Hi Takashi,
> I had to look at a previous patch to figure out CONFIG_SND_COHERENT_DMA
> is an arch dependent flag:
> +config SND_COHERENT_DMA
> + def_bool y
> + depends on !PPC32 || !NOT_COHERENT_CACHE
> + depends on !ARM
> + depends on !MIPS
> + depends on !PARISC
> In general, I don't expect this to be a compile time option.
Right now it has to be a compile-time option because
- dma_mmap_coherent() isn't implemented in every architecture (thus
fails to build), and
- pages allocated via dma_mmap_coherent() aren't always suitable for
> I'm wondering if extending the DMA API to provide an
> interface for user space to also be DMA coherent.
Yes, this would be really nice.
> Maybe something to talk about at Linux Plumbers Conf
> or kernel summit...
> > Do you guys see any pending issues? I'd love to merge these patches
> > into the upstream for 2.6.28.
> SPARC/SPARC64 usually falls into the same category as parisc/mips.
Right. I guess SH*, too.
But, a missing piece doesn't mean to stop pushing this :)
We can implement on other archs occasionally based on the existing