Ghost display on nvidia desktop GPUs

[WatchMkr]

No description provided.

[Drakulix]

This is simpledrm picking up the nvidia-gpu before the nvidia module is loaded.

To fix this we need to either enable nvidia's experimental fbdev-support (which had a lot of issues prior to 550) by also setting nvidia-drm.fbdev=1 or add a downstream kernel patch, like e.g. arch linux did: archlinux/linux@7bfc7b3

[ids1024]

Enabling the fbdev support could be good, but I don't know how that is in the current driver. I know it seemed a bit problematic when I tried it in the first driver that added it. It may be improved but is still "experimental" after all.

That kernel patch looks reasonable and straightforward, and including a patch Arch has generally seems alright.

[ids1024]

I guess it might also be possible for cosmic-comp to detect this situation in some way and ignore the simpledrm device node?

[Drakulix]

I guess it might also be possible for cosmic-comp to detect this situation in some way and ignore the simpledrm device node?

Maybe? There could be legitimate simpledrm devices though on an nvidia system. I am not sure how annoying it would be to figure out if they refer to the same device.

[ids1024]

The Arch patch seems to just be defining a static boolean that is set whenever nvidia-drm.modeset is set, that will prevent any simpledrm device from being created? If so then that would have the same issue.

It should be simple to filter out the simpledrm node. Though I see parameters like /sys/module/nvidia_drm/parameters/modeset aren't world-readable, unlike /proc/cmdline.

[XV-02]

For reference, the current fix effort:
pop-os/linux#332

[mmstick]

Fixed by pop-os/linux#332 and accompanying iso and distinst changes