Consulted the bug on #gnome-shell IRC. Next step is to track down the event that actually triggers execution of cogl_glib_source_dispatch. It's possible it simply does not arrive. BTW, this does not rule out Xorg as potential culprit, it might be simply not delivering the expected event. This is yet to be checked.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1873401 Title: Gnome Shell lock-up on GPU hotplug Status in mutter package in Ubuntu: New Bug description: Discovered when testing EVDI-backed screen (https://github.com/DisplayLink/evdi). While adding new device /dev/dri/cardX xorg locks, it can be observed by the cursors that stop blinking or menus not responding. Sometimes it is just a short (1-2 sec.) pause, but sometimes (hard to state the exact reproduction rate, rather rarely) the screen stops completely. Interestingly enough, if using HW cursor, it moves fine. Keyboard is at least partially functional, as it's possible to "bail out" to tty with C-A-Fx and kill the session. Anything else is difficult to check, as nothing really happens on the screen, it just remains frozen. When adding 4 GPUs at once (e.g. via config in /etc/modprobe.d according to https://support.displaylink.com/knowledgebase/articles/1843660-screen-freezes-after-opening-an-application-only). Haven't checked other numbers yet, to be done soon. The problem occurs, when adding the devices, not enabling their associated screens/reading EDID or anything like that. Also, to be checked with UDL, similar behaviour is expected, but due to the fact that it adds only a single device at a time reproducing "complete" freeze might be difficult. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xserver-xorg-core 2:1.20.8-2ubuntu2 ProcVersionSignature: Ubuntu 5.4.0-24.28-generic 5.4.30 Uname: Linux 5.4.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CasperMD5CheckResult: skip CompositorRunning: None CurrentDesktop: ubuntu:GNOME Date: Fri Apr 17 09:24:35 2020 DistUpgraded: Fresh install DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes, including running git bisection searches GraphicsCard: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller]) Subsystem: Dell 4th Gen Core Processor Integrated Graphics Controller [1028:060d] Subsystem: Dell GK107GLM [Quadro K1100M] [1028:060d] InstallationDate: Installed on 2020-04-16 (0 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200415) MachineType: Dell Inc. Dell Precision M3800 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-24-generic root=UUID=e0a7aba8-1c09-4367-9d6b-c74b73017fb4 ro quiet splash vt.handoff=7 SourcePackage: xorg-server UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/25/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: A12 dmi.board.name: Dell Precision M3800 dmi.board.vendor: Dell Inc. dmi.board.version: A12 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: Not Specified dmi.modalias: dmi:bvnDellInc.:bvrA12:bd05/25/2018:svnDellInc.:pnDellPrecisionM3800:pvrA12:rvnDellInc.:rnDellPrecisionM3800:rvrA12:cvnDellInc.:ct8:cvrNotSpecified: dmi.product.name: Dell Precision M3800 dmi.product.sku: Dell Precision M3800 dmi.product.version: A12 dmi.sys.vendor: Dell Inc. version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.101-2 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-1ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1873401/+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