Bug 510440 - Random Flickering on Desktop
Summary: Random Flickering on Desktop
Status: RESOLVED UPSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: compositing (other bugs)
Version First Reported In: 6.4.5
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-10-09 21:48 UTC by Wyatt Childers
Modified: 2025-10-12 20:56 UTC (History)
1 user (show)

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Latest Commit:
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Sentry Crash Report:


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Description Wyatt Childers 2025-10-09 21:48:55 UTC
SUMMARY
This is an odd one. I recently got this GIANT "57" Odyssey Neo G9" monitor.

Connecting the monitor to my graphics card and leveraging DisplayPort with:
- The full resolution
- 100% scaling
- HDR on
- Displayport 2.1 mode (monitor setting)
- FreeSync Premium On (monitor setting)
- Allow tearing in full-screen windows on

I *SOMETIMES* get variably bad graphical artificating. However, it only seems to happen when I'm using the desktop. The WEIRD part is if I open a full-screen game (e.g., Hunt Showdown) the artifacting stops. The EXTRA WEIRD part is that it also stops on the desktop after the game has been launched and remains fixed for hours (?)  after closing the game.

When the artifacting is happening, I've tried to narrow down what might be causing the problem by disabling HDR (in KDE), disabling FreeSync Premium (on the mointor), and by changing the maximum refresh rate in KDE and in the monitor settings. None of these changes seem to have an effect.

It ALMOST feels like an issue for https://gitlab.freedesktop.org/drm/amd/-/issues/ but at the same time, the games work fine. So it's kind of like KWin is doing something funny and some sort of buffer somewhere is getting corrupted until it's cleaned up by launching a full screen game (?)

Like I said, this is a REALLY weird one.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2
Kernel Version: 6.16.10-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 32 × AMD Ryzen 9 7950X 16-Core Processor
Memory: 64 GiB of RAM (61.9 GiB usable)
Graphics Processor 1: AMD Radeon RX 7900 XTX
Graphics Processor 2: AMD Radeon Graphics
Manufacturer: ASUS

ADDITIONAL INFORMATION
Comment 1 TraceyC 2025-10-09 21:59:26 UTC
Thanks for the bug report. That does sound odd. So we can narrow things down, would it be possible to send us a screen recording when the artifacts are happening?

Also, please provide the output of

kscreen-doctor -o
Comment 2 Wyatt Childers 2025-10-09 22:16:32 UTC
It looks like there's a driver issue stopping DisplayPort 2.1 from picking up on VRR (good to know and explains why the option wasn't present in the display settings). Looking around it looks like the kernel and AMDGPU are still a bit funky with DisplayPort 2.1.

Output: 1 DP-5 51046780-5a25-4933-9bc5-37575a80c0e6
        enabled
        connected
        priority 1
        DisplayPort
        replication source:0
        Modes:  1:7680x2160@120!  2:7680x2160@60  3:3840x1080@60  4:7680x2160@240*  5:3840x2160@240  6:3840x2160@120  7:3840x2160@120  8:3840x2160@60  9:3840x2160@60  10:3840x2160@30  11:3840x2160@30  12:5120x1440@240  13:5120x1440@120  14:5120x1440@60  15:3840x1080@240  16:3840x1080@120  17:2560x1440@240  18:2560x1440@120  19:2560x1440@60  20:1920x1080@240  21:1920x1080@120  22:1920x1080@120  23:1920x1080@60  24:1920x1080@60  25:1920x1080@60  26:1680x1050@60  27:1600x900@60  28:1280x1024@75  29:1280x1024@60  30:1440x900@60  31:1280x800@60  32:1152x864@75  33:1280x720@60  34:1280x720@60  35:1280x720@60  36:1024x768@75  37:1024x768@70  38:1024x768@60  39:800x600@75  40:800x600@72  41:800x600@60  42:720x480@60  43:720x480@60  44:640x480@75  45:640x480@60  46:640x480@60  47:1600x1200@60  48:1600x1200@240  49:1280x1024@240  50:1024x768@240  51:2560x1600@60  52:2560x1600@240  53:1920x1200@60  54:1920x1200@240  55:1280x800@240  56:3200x1800@60  57:3200x1800@240  58:2880x1620@60  59:2880x1620@240  60:1600x900@240  61:1368x768@60  62:1368x768@240  63:1280x720@240
        Geometry: 0,0 7680x2160
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: incapable
        RgbRange: unknown
        HDR: enabled
                SDR brightness: 500 nits
                SDR gamut wideness: 0%
                Peak brightness: 1015 nits, overridden with: 1015 nits
                Max average brightness: 604 nits
                Min brightness: 0 nits
        Wide Color Gamut: enabled
        ICC profile: none
        Color profile source: sRGB
        Color power preference: prefer efficiency and performance
        Brightness control: supported, set to 100% and dimming to 100%
        Color resolution: automatic (8), range: [8; 16] bits per color
        Allow EDR: unsupported

Perhaps interestingly ... the display port mode (to try some options) on the monitor to 1.4 and back to 2.1 made it come back. Changing back to 1.4 fixed it, but then coming back to 2.1 made it come back. So, perhaps the DisplayPort renegotiation is enough to reset whatever is happening as well.

I turned off VRR / FreeSync Premium on the monitor side BEFORE switching back to DisplayPort 2.1 this time; so I'll be curious to see if it comes back / if perhaps that itself did something.

Do you want a screen recording in software, or a video on my phone next time it happens?
Comment 3 TraceyC 2025-10-10 16:57:35 UTC
Since this does sound like a driver issue, your best bet is to report it via  https://gitlab.freedesktop.org/drm/amd/-/issues/ . I'll leave this in NEEDSINFO in case they say there's something we need to address on the KDE side.
Comment 4 Wyatt Childers 2025-10-12 20:56:35 UTC
I had an instance of this where launching a game didn't fix it; closing this in favor of: https://gitlab.freedesktop.org/drm/amd/-/issues/4638