Kernel 6.11 causes SDDM Wayland to just display a black screen if `fbdev=1` is not enabled

Description:

I upgraded to the latest kernel 6.11 and nvidia drivers today and got a black screen when SDDM (Wayland) loaded up. I could see my mouse cursor but I could not see anything else.

In the logs, I see:

Oct 01 18:54:15 arch-desktop sddm-helper-start-wayland[917]: "kwin_scene_opengl: No render nodes have been found, falling back to primary node\n"
Oct 01 18:54:15 arch-desktop sddm-helper-start-wayland[917]: "kwin_scene_opengl: 0x502: GL_INVALID_OPERATION error generated. <image> and <target> are incompatible\n"
Oct 01 18:54:15 arch-desktop sddm-helper-start-wayland[917]: "kwin_wayland_drm: Failed to create framebuffer: Invalid argument\n"

If I enable nvidia_drm.fbdev=1 in my kernel boot parameters, then everything works. However, since fbdev is still considered experimental, I feel like this is still a bug.

Additional info:

• package version(s):
  • linux 6.11.1.arch1-1
  • nvidia 560.35.03-9
  • nvidia-settings 560.35.03-1
  • nvidia-utils 560.35.03-4
  • lib32-nvidia-utils 560.35.03-1
  • opencl-nvidia 560.35.03-4
  • egl-gbm 1.1.2-1
  • egl-wayland 4:1.1.16-1
• config and/or log files: see above for relevant logs
• link to upstream bug report, if any: https://forums.developer.nvidia.com/t/drm-fbdev-wayland-presentation-support-with-linux-kernel-6-11-and-above/307920/5

Steps to reproduce:

1. Install linux 6.11 and the latest Nvidia drivers
2. Make sure fbdev=1 is not enabled
3. Boot into KDE Wayland. SDDM with Wayland enabled just displays a black screen.