Cortex A9 with ACP needing mixed coherency model

[Will Deacon]

On Fri, Aug 24, 2012 at 01:58:50AM +0100, John Linn wrote:
> It doesn't look like there's any good way to have a mixed coherency
> model to support using the ACP where there is coherency and using
> other ports where there is not coherency.
> ARM Linux kernel can support arch_is_coherent(), which means all DMA
> I/O is coherent. We have multiple DMA engines and they can go to thru
> coherent or non-coherent ports.
> 
> Am I missing something, or has someone figured out a way to deal with this?

Didn't Rob have a crack at fixing this with his recent DMA series?

  http://lists.infradead.org/pipermail/linux-arm-kernel/2012-August/113929.html

It's a really nice set of patches, so take a look.

Will