[PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs

Russell King - ARM Linux linux at arm.linux.org.uk
Mon Jun 20 11:06:10 EDT 2011


On Mon, Jun 20, 2011 at 11:45:41PM +0900, KyongHo Cho wrote:
> I still don't agree with your idea that change alloc_coherent() with alloc().
> As I said before, we actually do not need dma_alloc_writecombine() anymore
> because it is not different from dma_alloc_coherent() in ARM.

Wrong - there is a difference.  For pre-ARMv6 CPUs, it returns memory
with different attributes from DMA coherent memory.

And we're not going to sweep away pre-ARMv6 CPUs any time soon.  So
you can't ignore dma_alloc_writecombine() which must remain to sanely
support framebuffers.



More information about the linux-arm-kernel mailing list