| Summary: | [bisected] flickering in The Talos Principle | ||||||
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| Product: | xorg | Reporter: | Grazvydas Ignotas <notasas> | ||||
| Component: | Driver/intel | Assignee: | Chris Wilson <chris> | ||||
| Status: | RESOLVED FIXED | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||
| Severity: | normal | ||||||
| Priority: | medium | ||||||
| Version: | git | ||||||
| Hardware: | x86-64 (AMD64) | ||||||
| OS: | Linux (All) | ||||||
| Whiteboard: | |||||||
| i915 platform: | i915 features: | ||||||
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Description
Grazvydas Ignotas
2015-08-29 14:40:32 UTC
(Still waiting to complete a download of TTP) The usual reason for this is that the composited copy is delayed past the next vblank and so the assumption that the back buffer is safe to use again is false (and because the rendering by mesa is split across multiple batches in this case the compositor samples the back buffer in the middle of the rendering) or that the rendering just takes too long. The right fix is to be able to pass the buffer from the game to the compositor and only return it once the compositor has finished with it, alas that dream remains a long way off. What's the game setup you are using, or does it simply always happen once windowed? And of course there may be other reasons behind the flicker hence downloading a copy myself to investigate. There's a handsfree benchmark/demo under "extras". Does that flicker? What settings? Messing around with a Broadwell-U with cinnamon is not flickering in a windowed run of the benchmarks (with framerates varying between 6 and 60fps, ugh). OK it does depend heavily on resolution and settings. Playing along with them suggests that I originally selected the worst combination by chance as most changes make the issue go away. The "bad" settings are: resolution: 1440x900 graphics options -> performance: every setting on medium, max fps unlimited The issue is most visible on the "attract mode" - start the game, hit Esc on the company logos and wait for it to show several different scenes. The first scene (a wall with some drawings) is flickering and stuttering. The second one (architecture an a small pool) is stuttering even more but flickering less (fps counter shows ~50 but the framerate feels like it's below 10fps). The third scene with a statue is ok, and 4th one with a pool stutters heavily again. It does seem to be timing related and if your machine is rendering faster/slower I suspect you might not hit it, but moving to 7ae299be60 clearly solves the issue for me with the "bad" settings. I haven't seen this for a long while, so I'll just be optimistic and assume it somehow got fixed. Thanks for the follow-up! |
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