** Tags added: udeng-7632 ** Description changed:
[ Impact ] Since around about kernel 6.9, gdm3 fails to wait for a proper DRM kernel driver to load. So if your kernel driver is particularly slow (like dual AMD GPU systems in this case) then the login screen is displayed using simpledrm and software rendering. That wouldn't be a problem by itself except that a second or two later, the kernel "hotplugs" the old graphics card out and replaces it with the proper one. Mutter/GNOME currently cannot handle GPU hotplugging well and will usually freeze. [ Test Plan ] Ideally this should be executed by someone who experienced the issue in the first place (dual AMD GPU machines). Otherwise the login process should just be verified for robustness and the steps are the same: 1. Reboot the machine. 2. Expect the login screen to appear. 3. Log in immediately. 4. Expect the desktop appears. 5. Press Super or Super+A and expect the screen to animate. 6. Reboot the machine again. 7. Expect the login screen to appear. 8. Wait at least 20 seconds before logging in. 9. Expect the desktop appears. 10. Press Super or Super+A and expect the screen to animate. [ Where problems could occur ] Since the loop gating the start of the login screen itself is being modified, there is a risk that some part of the login experience could become broken or delayed. - [ Other Info (original report) ] + [ Other Info ] + + This issue likely affects more than just the two people who reported it + here because we're not counting anyone else who experiences a frozen + login screen and just didn't report the bug in enough detail. + + [ Original Description ] After upgrading to Ubuntu 25.04 my laptop fails to properly start the gnome login shell. During boot I see the graphical splash screen as expected, but once the login screen should show, one of the below things happen: - Nothing, I keep seeing the boot splash screen. - The login screen is rendered, but only a single frame. Moving the mouse or pressing keys has no effect. - The login screen is rendered and the mouse cursor moves, but none of the widgets respond to clicks or pressing keys. To recover, I have to Ctrl+Alt+F2 and login on the terminal interface. Then I can do a `sudo systemctl restart user-120.slice` after which I can go back to the GUI login screen and it works. ProblemType: Bug DistroRelease: Ubuntu 25.04 Package: gnome-shell 48.0-1ubuntu1 ProcVersionSignature: Ubuntu 6.14.0-22.22-generic 6.14.5 Uname: Linux 6.14.0-22-generic x86_64 ApportVersion: 2.32.0-0ubuntu5.2 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Jun 26 22:21:40 2025 DisplayManager: gdm3 InstallationDate: Installed on 2024-12-25 (183 days ago) InstallationMedia: Ubuntu 24.10 "Oracular Oriole" - Release amd64 (20241009.4) RelatedPackageVersions: mutter-common 48.1-1ubuntu3 SourcePackage: gnome-shell UpgradeStatus: Upgraded to plucky on 2025-06-15 (11 days ago) -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/2115451 Title: Since kernel 6.9, the login screen starts with simpledrm and switches to amdgpu one second later, causing freezes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/2115451/+subscriptions -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
