Update: The original apport report was generated using ubuntu-bug while the system was actively exhibiting the flickering/corruption symptoms with the 3-display configuration attached.
I performed additional testing and found a significant correlation with monitor configuration. With my original multi-monitor setup (2 ASUS monitors + 1 TCL TV), GNOME Shell produced repeated errors of the form: gbm_surface_lock_front_buffer failed Failed to query buffer age, got error 3003 These sessions also exhibited Activities Overview flickering, top-panel flickering, and occasional window-edge artifacts. The issue reproduced across multiple kernels, including mainline 7.0.12-070012-generic. On that kernel the symptoms appeared after roughly 10 minutes rather than several hours, suggesting the newer kernel affected time-to-failure but did not eliminate the issue. I have since tested using a single display only (Sony TV over HDMI) and have been unable to reproduce the problem. In the single-display configuration there is no visible flickering, no rendering corruption, and the GBM/buffer-age errors are absent. Error counts observed: 3-display configuration: journalctl -b | grep -c "gbm_surface_lock_front_buffer failed" => 4495 journalctl -b | grep -c "Failed to query buffer age" => 3967 Single-display configuration: journalctl -b | grep -c "gbm_surface_lock_front_buffer failed" => 0 journalctl -b | grep -c "Failed to query buffer age" => 0 Perhaps this appears to be a GNOME Shell/Mutter multi-monitor rendering issue, or an interaction involving multiple outputs, rather than a kernel-only or i915-only problem. This multi-monitor configuration was used for an extended period on Ubuntu 24.04 without exhibiting the Activities Overview flickering or related rendering corruption. The issue first appeared after upgrading to Ubuntu 26.04. While I cannot rule out other software changes that occurred as part of the upgrade, I did not observe this behavior on the same hardware prior to the upgrade. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2156644 Title: GNOME Panel & Activities Overview workspace thumbnails flickering issue To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2156644/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
