KWin Wayland session terminates when HDMI switch disconnects display (NVIDIA RTX 4090)

[ordinarybob]

Describe the bug

When using an HDMI switch with an NVIDIA RTX 4090 as the sole display output, switching away from the Bazzite system causes KWin Wayland to fail with framebuffer errors and terminate the entire user session. All running applications are killed.

Additionally, the display output is completely deinitialized—switching the HDMI back to the system does not restore the display. A full reboot is required.

Steps to Reproduce:

1. Boot Bazzite with RTX 4090 connected to an HDMI switch
2. Log in to Plasma Wayland session
3. Start some applications (terminal, browser, etc.)
4. Switch the HDMI switch to a different input
5. Entire session terminates, all applications killed, display does not return

Workarounds that resolved the issue:

1. Enable nvidia-persistenced: sudo systemctl enable nvidia-persistenced
2. Create /etc/modprobe.d/nvidia.conf with: options nvidia-drm modeset=1 fbdev=1
3. Regenerate initramfs: sudo rpm-ostree initramfs --enable
4. 4. Reboot

After these fixes, HDMI switching works correctly without killing the session.

What did you expect to happen?

KWin should gracefully handle temporary display disconnection and resume when the display reconnects, preserving the user session and running applications.

Session Logs

Jan 17 17:15:16 bazzite kwin_wayland[39530]: 0x500: GL_INVALID_ENUM error generated. Invalid <face>.
Jan 17 17:15:16 bazzite kwin_wayland[39530]: Invalid framebuffer status: "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT"
Jan 17 17:15:16 bazzite kwin_wayland[39530]: 0x502: GL_INVALID_OPERATION error generated. <image> and <target> are incompatible
Jan 17 17:15:16 bazzite kwin_wayland[39530]: Invalid framebuffer status: "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT"
Jan 17 17:15:16 bazzite kwin_wayland[39530]: Failed to create framebuffer: Invalid argument
Jan 17 17:15:19 bazzite kwin_wayland[39530]: atomic commit failed: Permission denied
Jan 17 17:15:20 bazzite kwin_wayland[39530]: PipeWire remote error: connection error
Jan 17 17:15:20 bazzite systemd[1866]: Stopping plasma-kwin_wayland.service - KDE Window Manager...
Jan 17 17:15:20 bazzite systemd[1866]: Stopped plasma-kwin_wayland.service - KDE Window Manager.

Hardware

Desktop PC

• GPU: NVIDIA GeForce RTX 4090
• Driver at time of issue: nvidia-open 580.95.05-1
• Current driver: 590.44.01 (nvidia-open)
• HDMI Switch: JCHICI 5-in-1-out 8K
• Display config: RTX 4090 is sole display output, no direct-connected monitors
• OS: Bazzite 43.20260101 (bazzite-nvidia-open:stable)
• Desktop: KDE Plasma 6.5.4
• KWin: 6.5.4 (Wayland)

Extra information or context

• When using the AMD integrated GPU instead of the RTX 4090, the display signal persisted correctly through HDMI switch changes (session behavior not verified).
• A driver update to 590.44.01 occurred during troubleshooting; there is a small possibility the driver update contributed to the fix, but the configuration changes are more likely responsible.
• This makes HDMI switches essentially unusable with NVIDIA GPUs on a default Bazzite installation.

Suggested Improvement:
Consider enabling nvidia-persistenced by default on Bazzite NVIDIA images, and/or shipping the nvidia-drm modeset=1 fbdev=1 options pre-configured. This would make NVIDIA GPUs work reliably with HDMI/DisplayPort switches out of the box.