wayland external monitor turned off for second user

[Johannes Timm]

Im using Gonome-Wayland for the login screen and user sessions on my hybrid (Intel+Nvidia) laptop.

When Im in the login screen all monitors are turned on (and display the mouse). The first user that logs in and starts its Wayland session can use all screens. This session is left running and the swithc user functionality is used to log into the other account. Here only the Laptop screen (intel) works, the external screen turns off (no signal). Within the login screen all screens work.

Im using the multiuser capabilities to distinguish between my "work" and "personal" user profile.

Its intended that both users and the login screen may use all screens at all times. Theoretically each user may have their personal set of devices using advanced features of loginctl.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: gnome-shell 42.5-0ubuntu1
ProcVersionSignature: Ubuntu 5.15.0-57.63-generic 5.15.74
Uname: Linux 5.15.0-57-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Jan 10 23:57:02 2023
DisplayManager: gdm3
InstallationDate: Installed on 2022-07-16 (178 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419)
RelatedPackageVersions: mutter-common 42.5-0ubuntu1
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

It looks likely that both displays are connected to the Intel GPU. And the recurring messages in the system log explain why one of them is blank:

  Failed to post KMS update: drmModeAtomicCommit: Invalid argument
  Page flip discarded: drmModeAtomicCommit: Invalid argument

So I think this is a duplicate of bug 1968040.