On Tue, Apr 27, 2021 at 08:01:13PM -0300, Jason Gunthorpe wrote:

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.

quoted

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.

We already have a mapping function that can return errors:
dma_map_sgtable.

I think it might make more sense to piggy back on that, as the sg_table
abstraction is pretty useful basically everywhere that we deal with
scatterlists anyway.

In the hopefully no too long run I plan to get rid of scatterlists in
at least NVMe and other high performance devices anyway.