On Tue, Apr 27, 2021 at 04:55:45PM -0600, Logan Gunthorpe wrote:

quoted

Also, I see only 8 users of this function. How about just fix them all
to support negative returns and use this as the p2p API instead of
adding new API?

Well there might be 8 users of dma_map_sg_attrs() but there are a very
large number of dma_map_sg(). Seems odd to me to single out the first as
requiring these changes, but leave the latter.

At a high level I'm OK with it. dma_map_sg_attrs() is the extra
extended version of dma_map_sg(), it already has a different
signature, a different return code is not out of the question.

dma_map_sg() is just the simple easy to use interface that can't do
advanced stuff.

I'm not that opposed to this. But it will make this series a fair bit
longer to change the 8 map_sg_attrs() usages.

Yes, but the result seems much nicer to not grow the DMA API further.

Jason