Public bug reported: Mesa 25.2.8-0ubuntu0.24.04.1 introduced a hang during monitor hotplug on dual-GPU laptops (Intel i915 + NVIDIA nouveau). The compositor (mutter/gnome-shell) hangs indefinitely when plugging in an external monitor.
When a monitor is hotplugged, mutter rebuilds its views and calls gbm_create_device on the compositor's main thread. Mesa's DRI screen initialization calls vkEnumeratePhysicalDevices, which goes through libVkLayer_MESA_device_select.so and calls wl_display_dispatch_queue, blocking in poll() waiting for a Wayland compositor response. Since the caller IS the compositor's main thread, it cannot service the request it is waiting for — a re-entrancy hang. Downgrading to mesa 25.0.7-0ubuntu0.24.04.2 fixes the issue completely. Upstream bug: https://gitlab.freedesktop.org/mesa/mesa/-/work_items/15168 Hardware: Lenovo ThinkPad with Intel Raptor Lake-P Iris Xe + NVIDIA AD107GLM RTX 2000 Ada Affected: mesa 25.2.8-0ubuntu0.24.04.1 Working: mesa 25.0.7-0ubuntu0.24.04.2 This is a significant regression as it makes external monitors completely unusable on affected dual-GPU laptops running Wayland. It also causes overnight freezes when HDMI-connected displays send hotplug detect signals during power state changes. Workaround: downgrade mesa packages to 25.0.7 and hold them. ** Affects: mesa (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2146386 Title: Mesa 25.2.8 regression: hang due to re-entrant Wayland dispatch during monitor hotplug (dual-GPU i915+nouveau) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/2146386/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
