On Tue, Dec 08, 2020 at 04:13:20PM +0900, Sergey Senozhatsky wrote: > On (20/12/08 13:54), Tomasz Figa wrote: > > > > In any case, Sergey is going to share a preliminary patch on how the > > current API would be used in the V4L2 videobuf2 framework. That should > > give us more input on how such a helper could look. > > HUGE apologies for the previous screw up! I replied in the > gmail web-interface and that did not work out as expected > (at all, big times). Actually the previous mail was a mime multipart one, and the plain text version displayed just fine here. My the gmail engineers finally learned something after all. > Another thing to notice is that the new API requires us to have two execution branches > in allocators - one for the current API; and one for the new API (if it's supported and > if user-space requested non-coherent allocation). So I think we do want these branches for coherent vs non-coherent as they have very different semantics and I do not think that hiding them under the same API helps people to understand those vastly different semantics. OTOH we should look into a fallback for DMA API instances that do not support the discontigous allocations. I think between your comments and those from Ricardo I have a good idea for a somewhat updated API. I'll try to post something in the next days.