On Fri, Sep 26, 2008 at 12:04:23PM +0200, Takashi Iwai wrote: > At Thu, 25 Sep 2008 15:55:53 +0100, > Pawel MOLL wrote: > > > > > One thing we can try is a patch like below. But, I'm not sure whether > > > this is correct over all architectures, too. At best, a generic API > > > would be helpful for such a thing... > > > + area->vm_page_prot = pgprot_noncached(area->vm_page_prot); > > > > Well, it's not enough, because the kernel mapping of buffer is still > > cached... A hack below does the job, but it is not nice as well... > > Yeah, that's not sexy, but maybe the only working case right now > (better with arch-specific ifdefs). > > IIRC, a similar buffer handling (via vmalloc) is used in video > drivers. I suppose they don't work as well, right? > DRM driver uses __vmalloc() with PAGE_KERNEL_NOCACHE, but it's only > for PPC32 non-coherent. > x86 does it also, via its PAGE_AGP definition. There are not that many platforms that define PAGE_KERNEL_NOCACHE though, so this gets a bit messy.. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
