On Wednesday 17 August 2011, Mark Salter wrote:

C6X is never consistent in that there is no hw snooping between main
memory and L2 cache. There is some cache control however which allows
us to create a pool of uncached memory for use as consistent DMA memory.
I think the __dma_is_coherent tries to tell at runtime if the dma handle
comes from such a pool of consistent memory.

I'm not aware of any drivers actually needing this although I'm sure TI
has some. For the purpose of getting the arch accepted, I could just
punt and take it out for now, simplifying the dma support. It can be
revisited later if needed.

Yes, sounds good. Not sure if you meant removing all calls to
arch_is_coherent() as well, but I'd suggest you do that, too.
This should further simplify the code by removing code paths
that are unused and untested.

	Arnd