Can't log in anymore after setting MUTTER_DEBUG_FORCE_KMS_MODE=simple

[Jorge Pérez Lara]

My laptop is running a Hybrid Nvidia RTX3060 + Intel i5 11400h graphics. After installing the Nvidia drivers and with Wayland (this doesn't happen with Xorg), once the screen is turned off (for example, by locking the screen or suspending the computer, it cannot be turned on.

This is a behavior similarish to the one in bug 1968040 (IDK if that one was also triggered by a screen lock, this one gets triggered inmediately after turning off the screen for whatever reason). In 22.04, I solved it quite easily by setting MUTTER_DEBUG_ENABLE_ATOMIC_KMS=0. As suggested in that ticket, I set this time MUTTER_DEBUG_FORCE_KMS_MODE=simple. I unfortunately cannot tell whether this would solve my issues because, when I reboot my computer with that variable, I simply cannot log in into my account. I type my password as usual (the login screen works perfectly, though) and then, once submited, the output is a black screen (LCD is on, though) and nothing shows up after.

ProblemType: Bug
DistroRelease: Ubuntu 22.10
Package: gnome-shell 43.0-1ubuntu2
ProcVersionSignature: Ubuntu 5.19.0-23.24-generic 5.19.7
Uname: Linux 5.19.0-23-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.23.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 24 08:40:12 2022
DisplayManager: gdm3
InstallationDate: Installed on 2022-09-26 (27 days ago)
InstallationMedia: Ubuntu 22.04.1 LTS "Jammy Jellyfish" - Release amd64 (20220809.1)
RelatedPackageVersions: mutter-common 43.0-1ubuntu4
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to kinetic on 2022-10-20 (3 days ago)

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

I can see bug 1968040 in the log, but that also shows that atomic KMS is in use whereas this bug should be about non-atomic KMS failing (MUTTER_DEBUG_FORCE_KMS_MODE=simple).

Please check for any crashes using https://wiki.ubuntu.com/Bugs/Responses#Missing_a_crash_report_or_having_a_.crash_attachment

Please also collect a system log from when MUTTER_DEBUG_FORCE_KMS_MODE=simple was in use. If it was the previous boot then run:

  journalctl -b-1 > prevboot.txt

and attach the resulting text file here.

[Jorge Pérez Lara (jorgesgk)]

Well, I wasn't using that one right now because, as I said, made me unable to use my computer. Will try to do as you suggest.

[Jorge Pérez Lara (jorgesgk)]

I just switched to the non-atomic KMS (MUTTER_DEBUG_FORCE_KMS_MODE=simple). My computer turned to black and turned unusable. I wasn't able to Crtl+Alt+F3 and switch to the terminal at all. Hopefully, I was able to change the /etc/environment to the default with a live CD and was able to boot again to my computer normally.

I can't see any crashes related to this (the last crash was yesterday, and this was a few minutes ago) in /var/crash. I can upload, though, the system log from the previous boot.

[Jorge Pérez Lara (jorgesgk)]

From the file, it would seem it actually booted into the session but didn't show anything...

[Daniel van Vugt (vanvugt)]

Thanks. It looks like the problem is:

oct 24 10:23:57 jorge-G5-KD gnome-shell[3546]: Failed to post KMS update: Failed to set mode 1920x1080_60.00 on CRTC 98: Invalid argument

Although I also notice you have unsupported graphics packages installed:

libdrm-amdgpu1 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]
libdrm-common 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]
libdrm-intel1 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]
libdrm-nouveau2 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]
libdrm-radeon1 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]
libdrm2 2.4.113+git2210180500.a81b9a~oibaf~j [origin: unknown]

Those packages happen to be responsible for the function that's failing above.

I'm going to see if I can reproduce the bug with the supported packages before blaming the oibaf PPA. Although it does often cause bugs (which we can't fix or support here).

[Daniel van Vugt (vanvugt)]

Ubuntu 22.10 on an Intel/Nvidia hybrid with driver 515 and MUTTER_DEBUG_FORCE_KMS_MODE=simple set is working for me. So it sounds like your oibaf PPA is the problem.

Please remove all PPAs from the machine, reboot, and then open new bugs for any issues you encounter.

[Jorge Pérez Lara (jorgesgk)]

Hi Daniel,

I'm **extremely** surprised to see this. I was not at all aware of using the obiaf PPAs. Let me check.

[Jorge Pérez Lara (jorgesgk)]

Reopened under this bug 1994019