Bug 446936 - git master - Cursor appears dark/corrupted with RDNA2 gpu under Wayland
Summary: git master - Cursor appears dark/corrupted with RDNA2 gpu under Wayland
Status: RESOLVED UPSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: core (other bugs)
Version First Reported In: git master
Platform: Compiled Sources Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL: https://gitlab.freedesktop.org/drm/am...
Keywords: regression
Depends on:
Blocks:
 
Reported: 2021-12-13 14:12 UTC by Jon Voss
Modified: 2022-09-08 16:37 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


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Description Jon Voss 2021-12-13 14:12:21 UTC
SUMMARY
Running the latest git master build of Plasma Wayland on a Radeon 6700XT, the cursor appears darker than it should be. Sort of a "corrupted" state. I believe this is related to the gamma changes in MR https://invent.kde.org/plasma/kwin/-/merge_requests/1335 - using the full gamma ramp from the kernel driver causes an issue with the coloring of the cursor. This happens under X11 as well, and not just with Plasma. Under X11, the issue can be mitigated by using the modesetting driver and disabling the UseGammaLUT option.

It looks like this is an issue with amdgpu, there has been an open issue over for quite a while:
https://gitlab.freedesktop.org/drm/amd/-/issues/1513

I would grab a screenshot, but it doesn't show up well. The best example is in the issue above.
Submitting this for awareness and tracking.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
Kernel Version: 5.15.7-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X 8-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: AMD Radeon RX 6700 XT
Comment 1 Jon Voss 2021-12-13 15:38:21 UTC
As suspected, reverting these commits in kwin made the cursor appear normal again:

3fb14035 backends/drm: only use atomic gamma size with AMS
4206046f Re-enable proper gamma ramps with AMS

I mispoke on the MR - the correct MR is:
https://invent.kde.org/plasma/kwin/-/merge_requests/1472
Comment 2 Zamundaaa 2021-12-20 10:58:21 UTC
If really necessary we can turn off proper gamma once again... but I'd rather not hide driver breakage all the time, especially not if it reduces color accuracy. This should be fixed upstream