29 May
2020
29 May
'20
8:59 a.m.
On Thursday, May 28, 2020 5:49 PM, Marek Olšák maraeo@gmail.com wrote:
On most hardware, there is a minimum pitch alignment for linear and any greater multiple of the alignment is fine.
On Navi, the pitch in bytes for linear must be align(width * bpp / 8, 256). That's because the hw computes the pitch from the width and doesn't allow setting a custom pitch. For that reason, multi-GPU sharing might not be possible if the other GPU doesn't align the pitch in exactly the same way.
OK. In this case I think it's fine to make the DMA-BUF import fail, as we've suggested on IRC. The more-or-less planned fix for these buffer sharing issues is to revive the buffer constraints proposal from the allocator project. It's a lot of work though.