Public bug reported: [ Impact ] When the kernel has been compiled with FB_EFI=n, FB_VESA=n, SIMPLEDRM=y a series of events can occur that cause simpledrm to race with GDM. When GDM loses the race then a user is left with a black screen.
This series of events doesn't currently happen in Jammy kernels, but can happen from a mainline kernel or HWE kernel that enables it. To protect users from this circumstance it is better to fix the race condition. This issue has been readily reproduced in Ubuntu and reported to upstream mutter. https://gitlab.gnome.org/GNOME/mutter/-/issues/2909 [ Test Plan ] * Ensure that a kernel with required kernel changes can boot to GDM using DRM driver (amdgpu, i915, or nouveau) [ Where Problems could occur ] * GDM can take longer to start up while settling [ Other Info ] * Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=2022385 * the changes needed to enable this in the kernel are tracked in bug 1965303 ** Affects: gdm3 (Ubuntu) Importance: Undecided Status: Fix Released ** Affects: gdm3 (Ubuntu Jammy) Importance: Undecided Status: New ** Also affects: gdm3 (Ubuntu Jammy) Importance: Undecided Status: New ** Changed in: gdm3 (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/2039757 Title: Fix race condition in gdm with simpledrm and real drm drivers Status in gdm3 package in Ubuntu: Fix Released Status in gdm3 source package in Jammy: New Bug description: [ Impact ] When the kernel has been compiled with FB_EFI=n, FB_VESA=n, SIMPLEDRM=y a series of events can occur that cause simpledrm to race with GDM. When GDM loses the race then a user is left with a black screen. This series of events doesn't currently happen in Jammy kernels, but can happen from a mainline kernel or HWE kernel that enables it. To protect users from this circumstance it is better to fix the race condition. This issue has been readily reproduced in Ubuntu and reported to upstream mutter. https://gitlab.gnome.org/GNOME/mutter/-/issues/2909 [ Test Plan ] * Ensure that a kernel with required kernel changes can boot to GDM using DRM driver (amdgpu, i915, or nouveau) [ Where Problems could occur ] * GDM can take longer to start up while settling [ Other Info ] * Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=2022385 * the changes needed to enable this in the kernel are tracked in bug 1965303 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/2039757/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
