Daniel et al, I wanted to provide an update based on the latest official mutter release as of today - 25.Mai.
The issue still exists. However, I provide the following in the event it helps to refine the underlying issue. Please let me know if there are logs that would be helpful to you or additional steps you would like me to take to help with the diagnosis. >From the desktop with dual monitors running: 1) Goto lock screen (win+l) 2) initial screen shows both monitors active 3) both screens go blac 4) external monitor goes into standby mode due to loss of signal 5) primary laptop displays turns on momentarily and a resolution change is observed based on the size of the mouse. 6) primary display goes black. 7) logging back in and going to display settings 8) system no longer uses external display and returns to single display 9) open gnome-control-center -> displays. Single Display is active 10) Attempt to select join displays 11) Error at the top of gnome-control-center: Changes cannot be applied - This could be due to hardware limitations 12) select mirror - click apply 13) a keep settings dialogue will pop-up briefly before the screen goes blank. When the screen comes back on, both screens come back on, with a new keep settings dialogue. 14) select keep settings. gnome-control-center now shows Joing Displays as being active. not/not mirror. ------------------------------------------------- As an additional note. If instead of going to the lock screen I suspend the system, which includes both monitors going into sleep mode, the above issue is not observed. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-control-center in Ubuntu. https://bugs.launchpad.net/bugs/1877226 Title: nvidia - external display unavailable after screen goes to sleep Status in gnome-control-center package in Ubuntu: New Status in mutter package in Ubuntu: New Status in nvidia-graphics-drivers-440 package in Ubuntu: New Bug description: On ubuntu 20.04 (Linux 5.4.0-29-generic #33-Ubuntu SMP Wed Apr 29 14:32:27 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux) with nvidia proprietary driver 440.64 with an nvidia MX250 (Lenovo T590): 1) Attach monitor via HDMI 2) Monitor is properly detected. Gnome-control-center sees the correct monitor and sets it to join displays. No issue 3) activate lock screen (window key + L) 4) wait for screens to go to sleep 5) wake up screens to login again (external monitor flashes briefly) 6) login 7) system no longer uses external display and returns to single display 8) open gnome-control-center -> displays. Single Display is active 9) Attempt to select join displays 10) Error at the top of gnome-control-center: Changes cannot be applied - This could be due to hardware limitations 11) select mirror - click apply 12) a keep settings dialogue will pop-up briefly before the screen goes blank. When the screen comes back on, both screens come back on, with a new keep settings dialogue. 13) select keep settings. gnome-control-center now shows Joing Displays as being active. not/not mirror. Notes: -changing prime-select to nvidia vs adaptive does not change the issue -setting power profile to performance in nvidia-settings does not change the issue gnome-control-center info: Installed: 1:3.36.1-1ubuntu5 Candidate: 1:3.36.1-1ubuntu5 Version table: *** 1:3.36.1-1ubuntu5 500 500 http://de.archive.ubuntu.com/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status nvidia-driver-440: Installed: 440.82+really.440.64-0ubuntu6 Candidate: 440.82+really.440.64-0ubuntu6 Version table: *** 440.82+really.440.64-0ubuntu6 500 500 http://de.archive.ubuntu.com/ubuntu focal/restricted amd64 Packages 100 /var/lib/dpkg/status ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: gnome-control-center 1:3.36.1-1ubuntu5 ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30 Uname: Linux 5.4.0-29-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu May 7 06:16:15 2020 ExecutablePath: /usr/bin/gnome-control-center InstallationDate: Installed on 2020-04-24 (12 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) SourcePackage: gnome-control-center UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1877226/+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
