I can imagine some delays could be mutter's fault... (just a theory)
If we get a burst of a number of new connector/hotplug/udev events and mutter tries to action each one immediately then it will take a long time and lots of flashing to get through all of them. To avoid that, mutter should be ignoring such events for some short period so that it can group them into a single config change that will complete faster. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1859955 Title: Display freaks out when external monitors are attached Status in gnome-shell package in Ubuntu: New Status in mutter package in Ubuntu: New Bug description: Running Focal on my ThinkPad T450, but not unique to this release as it happened on 19.10 (and probably older releases too). Steps to reproduce. While running GNOME Shell, attach the laptop to additional external monitors. (I'm using a docking station, but equally you can attach them via the video ports on the laptop itself) Expected outcome Desktop on 1 monitor goes away. Desktop comes back on N monitors. Actual outcome Laptop display goes black Laptop display comes back, moved 50% horizontally One external monitor comes on Laptop display goes back to normal Second external monitor comes on All three displays go off again Laptop display comes on again alone Laptop display goes off again laptop display comes on again External monitors come back on again System is usable. The entire process takes twenty seconds. https://www.youtube.com/watch?v=QuSudpxVOao ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: gnome-shell 3.34.3-1ubuntu1 ProcVersionSignature: Ubuntu 5.4.0-9.12-generic 5.4.3 Uname: Linux 5.4.0-9-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu15 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Thu Jan 16 10:21:05 2020 DisplayManager: gdm3 InstallationDate: Installed on 2018-02-04 (710 days ago) InstallationMedia: neon userlts "Xenial" - Build amd64 LIVE Binary 20180202-11:07 RelatedPackageVersions: mutter-common 3.34.3-1ubuntu1 SourcePackage: gnome-shell UpgradeStatus: Upgraded to focal on 2020-01-08 (7 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1859955/+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
