Messages in this thread | | | From | Rob Clark <> | Date | Tue, 9 Aug 2022 08:01:04 -0700 | Subject | Re: DMA-buf and uncached system memory |
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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
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