Re: DMA API issues

From: Russell King
Date: Wed Jun 23 2004 - 10:45:49 EST


On Wed, Jun 23, 2004 at 05:36:57PM +0200, Takashi Iwai wrote:
> > and a similar one for the ARM-specific "write combining" case (for
> > framebuffers utilising the DMA API)?
>
> pgprot_noncached() is used on many other architectures in fbmem.c
> (well, not really, but the result is identical).
> Should it be provided as another one, or is it used as default in
> dma_mmap_coherent()?

The whole point is to kill the idea that drivers should have to know
about page protection crap. That should be wholely contained within
the architecture implementation.

> Also, it would be nice to have a version for sg-buffer, too.

Well, we don't have a sg-buffer version of dma_alloc_coherent(),
so we don't have a sg-buffer version of dma_mmap_coherent().

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
2.6 Serial core
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