On Wed, 2008-08-27 at 07:42 +0200, Takashi Iwai wrote: > 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 */ > > +#else > > +#define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */ > > +#endif > > > > 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 > SG-mapping. This is trivially fixable by the usual methods, so, as Grant says, we should employ them rather than non-standard ways of doing this Basically, you're asking to extend the DMA API, so this should be taken to linux-arch. That way, it might also give visibility to the graphics people and we can negotiate over a unified API. James
