Black screen on SDDM/Wayland on first boot with Nvidia card

[agorgl]

Describe the bug

Fresh installation of latest bazzite-nvidia (I believe currently on version 3.5.1), boots into black screen.
This seems to be another Wayland <-> Nvidia compatibility problem because similar behavior is exibited by plasma when started manually with startplasma-wayland from a tty.
Both SDDM and Plasma work fine in X11 mode

What did you expect to happen?

See SDDM in order to be able to login, login to functional Plasma environment

Output of rpm-ostree status

State: idle
Deployments:
● ostree-image-signed:docker://ghcr.io/ublue-os/bazzite-nvidia:stable
                   Digest: sha256:89a4a6c1383698d407404343ee36eadaea53d31e9dd19ee6791e71082757097b
                  Version: 40.20240714.0 (2024-07-14T16:27:45Z)

  ostree-image-signed:docker://ghcr.io/ublue-os/bazzite-nvidia:stable
                   Digest: sha256:0e152de42de6781cc8249573ad875e10804a568d3658de39e8379405440065fd
                  Version: 40.20240714.0 (2024-07-14T16:27:45Z)

Hardware

nvidia card: RTX A1000 Laptop GPU

Extra information or context

nvidia kernel module version: 555.58.02

[agorgl]

Some more notes:

The above problem was reproduced in a linux vm with pci passthrough (vfio).
It seems that the problem occurs when both a spice display and the pci passthrough are assigned to the vm.

After removing spice display and virtio video (and all their dependencies) from vm details in virt-manager, bazzite sddm/plasma with wayland seems to work normally.

[agorgl]

Keep in mind that this is something I tried for the first time, so I don't know if its a plasma-wayland with multiple video cards (virtio vga/spice + real pci card) issue or a nvidia driver issue.

In any case I'll leave it open a little bit for further feedback, and I'll close this soon because it seems irrelevant with the bazzite project.

[ageisen2000]

I'm also getting this without doing it from a VM. A maintainer on discord mentioned that this could be an HDR bug.

[agorgl]

Yeah I saw similar mentions to HDR problems with the nvidia 555 driver:
https://bbs.archlinux.org/viewtopic.php?id=297236
https://bugs.kde.org/show_bug.cgi?id=488941
https://forums.developer.nvidia.com/t/nvidia-555-52-04-plasma-6-1-wayland-screen-turn-off-on-login/297197

I'm not sure this is the case here though, because I checked in ~/.config/kwinoutputconfig.json, and both "highDynamicRange" and "wideColorGamut" where set to false.

The problem went away only when I removed the spice/virtio device from virt-manager in my case which is really inconvenient because I need to plug a real monitor to my gpu that is being passed through in order to see the vm output

[ageisen2000]

Yes, I personally don't believe it's an HDR issue because I'm having the same problem from a live USB and it generally has HDR disabled by default. I don't know enough to troubleshoot the issue though. I can provide more logs, I just need to know what commands to run.

[ageisen2000]

This seems really close to what I've been experiencing. Looks like it's potentially a bug with KDE

https://bugs.kde.org/show_bug.cgi?id=488941

[agorgl]

Another discussion that might have relevant info:
https://forums.developer.nvidia.com/t/555-release-feedback-discussion/293652/45?page=3