On Thu, 2023-03-09 at 14:34 +0200, Ville Syrjälä wrote: > On Thu, Mar 09, 2023 at 12:09:55PM +0100, Maarten Lankhorst wrote: > > > > On 2023-03-09 12:04, Hogander, Jouni wrote: > > > On Mon, 2023-03-06 at 22:58 +0200, Ville Syrjälä wrote: > > > > On Mon, Mar 06, 2023 at 09:23:50PM +0100, Maarten Lankhorst > > > > wrote: > > > > > Hey, > > > > > > > > > > On 2023-03-06 16:23, Souza, Jose wrote: > > > > > > On Mon, 2023-03-06 at 15:16 +0100, Maarten Lankhorst wrote: > > > > > > > As a fallback if we decide not to merge the frontbuffer > > > > > > > tracking, allow > > > > > > > i915 to keep its own implementation, and do the right > > > > > > > thing in > > > > > > > Xe. > > > > > > > > > > > > > > The frontbuffer tracking for Xe is still done per-fb, > > > > > > > while > > > > > > > i915 can > > > > > > > keep doing the weird intel_frontbuffer + i915_active > > > > > > > thing > > > > > > > without > > > > > > > blocking Xe. > > > > > > Please also disable PSR and FBC with this or at least add a > > > > > > way > > > > > > for users to disable those features. > > > > > > Without frontbuffer tracker those two features will break > > > > > > in some > > > > > > cases. > > > > > FBC and PSR work completely as expected. I don't remove > > > > > frontbuffer > > > > > tracking; I only remove the GEM parts. > > > > > > > > > > Explicit invalidation using pageflip or CPU rendering + > > > > > DirtyFB > > > > > continue > > > > > to work, as I validated on my laptop with FBC. > > > > Neither of which are relevant to the removal of the gem hooks. > > > > > > > > Like I already said ~10 times in the last meeting, we need a > > > > proper > > > > testcase. Here's a rough idea what it should do: > > > > > > > > prepare a batch with > > > > 1. spinner > > > > 2. something that clobbers the fb > > > > > > > > Then > > > > 1. grab reference crc > > > > 2. execbuffer > > > > 3. dirtyfb > > > > 4. wait long enough for fbc to recompress > > > > 5. terminate spinner > > > > 6. gem_sync > > > > 7. grab crc and compare with reference > > > > > > > > No idea what the current status of PSR+CRC is, so not sure > > > > whether we can actually test PSR or not. > > > > > > > CRC calculation doesn't work with PSR currently. PSR is disabled > > > if CRC > > > capture is requested. > > > > > > Are we supposed to support frontbuffer rendering using GPU? > > > > No other driver does that. > > Every driver does that when you run X w/o a compositor. Assuming > there is an actual GPU in there. > > > It's fine if DirtyFB hangs instead until the > > job it waits on completes. > > No one tried to make it just wait for the fence(s) w/o doing > a full blown atomic commit. It might work, but might also > still suck too much. I guess depends on how overloaded the GPU > is. > > What we could do is do a frontbuffer invalidate on dirtyfb > invocation, and then once the fence(s) signal we do a frontbuffer > flush. That would most closely match the gem hook behaviour, except > the invalidate comes in a bit later. The alternative would be to > skip the invalidate, which should still guarantee correctness in > the end, just with possibly jankier interactivity. > I have implemented this approach here: https://patchwork.freedesktop.org/series/116620/ Review/comments are welcome. BR, Jouni Högander
