On Thursday, May 07, 2015 11:07:08 AM Arnd Bergmann wrote:

On Wednesday 06 May 2015 17:16:35 Suravee Suthikulanit wrote:

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On 5/6/2015 5:21 PM, Rafael J. Wysocki wrote:

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+      bool
+
+config ACPI_SUPPORT_CCA_ZERO

I guess this means "we support devices that can DMA, but are not coherent".
right?

Yes, basically when _CCA=0.

So what about

      ARCH_SUPPORT_CACHE_INCOHERENT_DMA

Since this is specific to ACPI _CCA, I just want to be clear with the 
naming.

How about directly using the architecture names here, this is inherently
architecture specific, and it's more likely that if another architecture
gets added in the future that it will have other requirements.

Sounds reasonable to me.

Rafael