Re: [PATCH V5 1/3] dma-mapping: Introduce device_is_coherent() as a helper

[Christoph Hellwig]

On Mon, Sep 18, 2017 at 12:21:40PM +0800, Huacai Chen wrote:
> We will use device_is_coherent() as a helper function, in order to set
> an appropriate dma alignment in dmapool and block queue (other patches
> in this series).
> 
> There is a MIPS-specific plat_device_is_coherent(), but we need a more
> generic solution, so add and use a new function pointer in dma_map_ops.

This is still missing any explanation on what this API could do
with the information, and both of the callers in the series don't
actually need it.