Hi, On 4 April 2017 at 09:31, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Tue, Apr 04, 2017 at 06:13:20PM +1000, raof@xxxxxxxxxx wrote: >> Until recently, on (at least) nouveau, radeon, and amdgpu attempting to scanout of an >> imported dma-buf would silently result in the dma-buf sharing being broken. >> >> While the hardware is capable of scanning out of imported dma-bufs (at least in some circumstances), >> these drivers do not currently implement it, so attempts to scan out of such buffers will never succeed. >> >> Add a userspace-visible drm capability and associated driver_feature so that userspace can discover >> when scanning out of an imported dma-buf can work. >> >> Signed-off-by: Christopher James Halse Rogers <christopher.halse.rogers@xxxxxxxxxxxxx> > > This seems like an awful specific special case. Why can't you do the > entire dance upfront, i.e. import buffer, addfb2? None of that has any > visible effect, and it will also allow you to check runtime constraints > which can't be covered with this here. Oh, that already happens. Chris sent out a series which fixes bugs for PRIME import across a few drivers, mostly ones which need to pin scanout buffers to dedicated memory. So this cap is basically DRM_CAP_PRIME_SCANOUT_ISNT_BUGGY. FWIW, I'm fairly skeptical about adding caps which essentially declare the absence of bugs like this. Cheers, Daniel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
