[PATCH RFC 0/3] riscv: Add DMA_COHERENT support

[Christoph Hellwig]

On Wed, May 19, 2021 at 01:48:23PM +0800, Guo Ren wrote:
> The patchset just leaves a configuration chance for vendors. Before
> RISC-V ISA fixes it, we should give the chance to let vendor solve
> their real chip issues.

No.  The vendors need to work to get a feature standardized before
implementing it.  There is other way to have a sane kernel build that
supports all the different SOCs.