Qubes only detects one monitor

I’m a new user of Qubes and am having trouble getting my second monitor to work.

I’m not sure where to even start debugging the problem. I was previously using another distro and the hardware worked fine.

It is detected in System Settings > Display?

No. Only one monitor is detected.

The only way that I can get Qubes to boot is if I press ‘e’ on the grub screen and then append ‘nomodeset’ to the module2 command. Is this the reason why Qubes cannot detect the second monitor?

I’m new to kernel parameters but not new to linux. When I disable ‘nomodeset’ I get a black screen during boot, before I input the LUKS password. When I re-enable nomodeset, qubes boots with only one monitor.

In xorg.0.log.old it says “(EE) [drm] failed to open DRM device for pci:0000:2b:00.0: -19”.

According to lsmod the nouveau module has loaded. There are no errors in journalctl about nouveau. I don’t have any modules blacklisted in modprobe.d.

Any advice?

Does seem like an issue with loading the proper driver but not sure how to help. What hardware are you using?

Same problem here. After install Q 4.2.3 this starts do happens. It’s nothing about nvidia driver installation. Using nouveau and have same problem. Kernel 6.6.54-1.qubes.fc37.x86_64 and the same with 6.6.48…

I have a nvidia 1080 titanium graphics card.

did you try with nvidia proprietary drivers?

I fixed the problem that I was having. The cause of the problem is a bug in the newest version of the linux kernel that affects some nvidia cards. I fixed the problem by downgrading my kernel to an earlier version, before the bug crept in. Hopefully Linus will fix it soon.

I’m currently running kernel version 6.1.75-1. With this kernel version nouveau starts up without any issues on my machine and I have two monitors.

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