Re: [GIT PULL] dma mapping fixes for 4.17-rc3

From: Christoph Hellwig
Date: Wed Apr 25 2018 - 02:59:37 EST

On Tue, Apr 24, 2018 at 11:54:26PM -0700, David Rientjes wrote:
> Shouldn't that test for dev->coherent_dma_mask < DMA_BIT_MASK(32) be more
> accurately <=?

No, it should really be <. The exactly 32-bit case is already covered
with GFP_DMA32. Eventualy it should be < 24-bit with a separate
GFP_DMA32 case for > 32-bit && < 64-bit. Takashi has been working on
that, but it is 4.18 material.