On Mon, Feb 15, 2021 at 12:58 AM Christian König christian.koenig@amd.com wrote:
Hi guys,
we are currently working an Freesync and direct scan out from system memory on AMD APUs in A+A laptops.
On problem we stumbled over is that our display hardware needs to scan out from uncached system memory and we currently don't have a way to communicate that through DMA-buf.
For our specific use case at hand we are going to implement something driver specific, but the question is should we have something more generic for this?
I'm a bit late to this party (and sorry, I didn't read the entire thread), but it occurs to me that dmabuf mmap_info[1] would also get you what you need, ie. display importing dma-buf could check whether the exporter is mapping cached or not, and reject the import if needed?
[1] https://patchwork.freedesktop.org/patch/496069/?series=106847&rev=2
After all the system memory access pattern is a PCIe extension and as such something generic.
Regards, Christian. _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel