Bug 514051

Summary: kwin_wayland issue with GPU and iGPU setup
Product: [Plasma] kwin Reporter: Gabe Morris <gabemorris1231>
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: NEEDSINFO WAITINGFORINFO    
Severity: normal CC: kdedev, xaver.hugl
Priority: NOR    
Version First Reported In: 6.5.4   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Bug Depends on:    
Bug Blocks: 506893    
Attachments: drm_info output
journalctl output

Description Gabe Morris 2026-01-01 18:48:38 UTC
SUMMARY
KWin/Wayland fails to initialize correctly on NVIDIA dGPU at session start.  
When the display is connected to the NVIDIA GPU at boot, the BIOS splash appears, but the screen goes black when KWin/SDDM should appear. After logging in via the Intel iGPU output and then switching the monitor back to the NVIDIA GPU, KWin shows abnormally high GPU usage until `kwin_wayland --replace` is executed. Restarting KWin immediately restores normal functionality and GPU usage.

STEPS TO REPRODUCE
1. Boot system with monitor connected to NVIDIA HDMI output.
2. BIOS splash displays, then screen goes black instead of showing SDDM.
3. Move monitor cable to Intel iGPU HDMI and log in.
4. Move monitor cable back to NVIDIA HDMI.
5. Observe high GPU usage until running `kwin_wayland --replace &`.

## OBSERVED RESULT
- No display output from NVIDIA GPU during login (black screen).
- KWin initializes in an unstable state when session begins.
- GPU usage abnormally high.
- Running `kwin_wayland --replace` resets GPU usage to expected idle (~1%) and restores proper compositing.
- Console output contains EGL context errors, for example:
  - `QWaylandGLContext: Failed to create the decorations EGLContext. Decorations will not be drawn.`

## EXPECTED RESULT
- KWin should start with hardware acceleration correctly active on the NVIDIA GPU from the start of the session.
- No need to hot-switch display cables or restart KWin.
- Normal GPU usage at idle without manual interaction.

## SOFTWARE/OS VERSIONS
- Fedora Linux 43 (KDE Plasma Desktop Edition)
- Kernel: 6.17.12-300.fc43.x86_64
- KDE Plasma: 6.5.4
- KWin: 6.5.4
- SDDM: 0.21.0-10.fc43
- Session type: Wayland
- GPU: Intel UHD Graphics 770 (i915) + NVIDIA GeForce RTX 5060 Ti
- NVIDIA driver: 580.119.02 (proprietary)
- Monitor connection: HDMI (primary attempt on NVIDIA; iGPU used as fallback)
- Secure Boot: enabled
Comment 1 TraceyC 2026-01-05 17:58:02 UTC
Thanks for the bug report. Can you provide us some system information so we can investigate?

1. Copy the output of this into the report:

kscreen-doctor -o

2. Please attach the output of drm_info after triggering the issue

3. Also attach kwin's logs when the high GPU usage occurs

  journalctl --boot --user-unit plasma-kwin_wayland > ~/log.txt

Thanks!
Comment 2 TraceyC 2026-01-05 17:58:21 UTC
.
Comment 3 Gabe Morris 2026-01-06 02:21:19 UTC
Created attachment 188252 [details]
drm_info output
Comment 4 Gabe Morris 2026-01-06 02:21:46 UTC
Created attachment 188253 [details]
journalctl output
Comment 5 Gabe Morris 2026-01-06 02:22:24 UTC
In addition to the above attachments, here is the output of the first item requested:

kscreen-doctor -o
Output: 1 HDMI-A-3 f148c46d-810d-4a60-a8b6-bd5ed05782db
        enabled
        connected
        priority 1
        HDMI
        replication source:0
        Modes:  1:3840x2160@60.00*!  2:4096x2160@59.94  3:4096x2160@29.97  4:4096x2160@24.00  5:4096x2160@23.98  6:3840x2160@59.94  7:3840x2160@29.97  8:3840x2160@23.98  9:1920x1080@60.00  10:1920x1080@59.94  11:1920x1080@29.97  12:1920x1080@23.98  13:1680x1050@59.95  14:1280x1024@60.02  15:1440x900@59.89  16:1280x960@60.00  17:1280x800@74.93  18:1280x800@59.81  19:1280x720@60.00  20:1280x720@59.94  21:1280x720@29.97  22:1280x720@23.98  23:1024x768@60.00  24:800x600@60.32  25:800x600@56.25  26:720x480@59.94  27:640x480@59.94  28:640x480@59.93 
        Geometry: 0,0 1920x1080
        Scale: 2
        Rotation: 1
        Overscan: 0
        Vrr: incapable
        RgbRange: unknown
        HDR: disabled
        Wide Color Gamut: disabled
        ICC profile: none
        Color profile source: sRGB
        Color power preference: prefer efficiency and performance
        Brightness control: supported
Comment 6 Gabe Morris 2026-01-06 02:23:24 UTC
(In reply to TraceyC from comment #2)
> .

All the above reports were done while the issue was persisting - before I fix it with kwin_wayland --replace
Comment 7 TraceyC 2026-01-08 21:09:49 UTC
Thanks for the detailed logs. The kwin developers will need to take a look.
Comment 8 Zamundaaa 2026-01-09 14:14:46 UTC
When you say "then screen goes black", do you mean that it has no signal / turns off completely, or that it shows a black image?
The output from drm_info while the screen is black would be useful. You can get it through ssh from another device.

Also, when it happens, can you switch to a tty, log in, and run startplasma-wayland from there? If yes, does that give you a working session?
Comment 9 Gabe Morris 2026-01-10 04:34:35 UTC
(In reply to Zamundaaa from comment #8)
> When you say "then screen goes black", do you mean that it has no signal /
> turns off completely, or that it shows a black image?
> The output from drm_info while the screen is black would be useful. You can
> get it through ssh from another device.
> 
> Also, when it happens, can you switch to a tty, log in, and run
> startplasma-wayland from there? If yes, does that give you a working session?

The last sudo dnf update that I ran yesterday included updates for my kernel. Something in the update fixed the issue, so fee free to close the issue. I'll let y'all know if there are any further complications.