Thanks for the investigation Daniel. Indeed my inability to change the scale with the first patch was due to low resolution in my client machine.
Interesting enough, I tried reproducing this in a Local VM with Xdcv (with just regular mutter packages, straight from our archives, no PPA), and I'm unable to reproduce the problem when I disable fractional scaling. I'm able to change to 200% and then revert properly. Given that I'm unable to reproduce there, I went back to an AWS Workspace and installed your new 42.5-0ubuntu1vv2 package and I'm still able to reproduce the problem when reverting it: May 31 20:17:42 U-3JQHCWI1WR5QW geoclue[2660]: Service not used for 60 seconds. Shutting down.. May 31 20:17:42 U-3JQHCWI1WR5QW systemd[1]: geoclue.service: Deactivated successfully. May 31 20:17:43 U-3JQHCWI1WR5QW gnome-shell[3188]: Failed to use linear monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 31 20:17:43 U-3JQHCWI1WR5QW gnome-shell[3188]: Failed to use fallback monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 31 20:17:43 U-3JQHCWI1WR5QW gnome-shell[3188]: Impossible to set scaling on crtc 59 to 1.000000, error id 2 May 31 20:17:43 U-3JQHCWI1WR5QW gnome-shell[3188]: Xlib: extension "DPMS" missing on display ":1". May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-0' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-1' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-2' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-3' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-0' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-1' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-2' does not exist May 31 20:17:43 U-3JQHCWI1WR5QW gsd-color[3358]: could not find device: property match 'XRANDR_name'='VNC-output-3' does not exist -- 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/2020782 Title: Xdcv: Changing display scale setting and reverting it fails Status in mutter package in Ubuntu: New Bug description: In Amazon Workspaces running Ubuntu 22.04, when attempting to change the Scale in the Gnome Display settings, if you click on a different scale (i.e. changing from 100% to 200%) and hitting apply, it will bring up a prompt asking if you want to keep or revert the changes and there will be a timer of 20 seconds. If you try to revert the changes (either by letting the timer expire or by clicking the "revert" button), we will hit one of the following two behaviors: 1 - The setting won't revert and will keep scaled 2 - gnome-shell will show some error messages in syslog and the display will be "corrupted", where the only window you are able to click is the display setting and if you try to drag it, it will leave a "blur" throughout the window (per discussions, this seems to be https://launchpad.net/bugs/1924689) For both situations, changing the display resolution (i.e. going into and out of full screen in the workspaces client) will fix the issue When hitting situation 1, syslog shows: May 17 17:33:10 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to restore previous configuration: Invalid mode 1920x1080 (19.958942) for monitor 'unknown unknown' When hitting situation 2, syslog shows: May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to restore previous configuration: Invalid mode 1920x984 (19.895834) for monitor 'unknown unknown' May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use stored monitor configuration: Invalid mode 1920x984 (19.895834) for monitor 'unknown unknown' May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use linear monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use fallback monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Impossible to set scaling on crtc 59 to 1.000000, error id 2 May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Xlib: extension "DPMS" missing on display ":1". May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: Object St.Label (0x557090d07de0), has been already disposed — impossible to access it. This might be caused by the object having been destroyed from C code using something such as destroy(), dispose(), or remove() vfuncs. May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: == Stack trace for context 0x557090bee180 == May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: #0 557093f00e68 i /usr/share/gnome-shell/extensions/ubuntu-d...@ubuntu.com/appIcons.js:1349 (2cdac32b2e20 @ 105) May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: #1 557093f00dd8 i /usr/share/gnome-shell/extensions/ubuntu-d...@ubuntu.com/dash.js:42 (2cdac32a5d80 @ 27) May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: #2 557093f00d58 i resource:///org/gnome/shell/ui/dash.js:545 (20c3e0d20970 @ 24) May 17 17:31:24 U-1AZMIM8SIPZ6I gnome-shell[3030]: JS ERROR: TypeError: monitor is null#012_updateWorkAreaBox@resource:///org/gnome/shell/ui/overviewControls.js:58:26#012_init/<@resource:///org/gnome/shell/ui/overviewControls.js:51:45 Sometimes the stack trace isn't shown, but the symptom is the same: May 17 18:31:39 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to restore previous configuration: Invalid mode 1920x984 (19.895834) for monitor 'unknown unknown' May 17 18:31:39 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use stored monitor configuration: Invalid mode 1920x984 (19.895834) for monitor 'unknown unknown' May 17 18:31:39 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use linear monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 17 18:31:39 U-1AZMIM8SIPZ6I gnome-shell[3030]: Failed to use fallback monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown' May 17 18:31:39 U-1AZMIM8SIPZ6I gnome-shell[3030]: Impossible to set scaling on crtc 59 to 1.000000, error id 2 May 17 18:31:40 U-1AZMIM8SIPZ6I gnome-shell[3030]: Xlib: extension "DPMS" missing on display ":1". I'm unable to reproduce the problem if I manually install ubuntu-desktop and use the Nice DCV Server (as used by Workspaces) by following the steps from (using the xorg-x11-drv-dummy): https://docs.aws.amazon.com/dcv/latest/adminguide/setting-up- installing-linux.html One relevant difference is that Workspaces uses a custom X11 server /usr/bin/Xdcv, instead of /usr/lib/xorg/Xorg, and they have the following process being started: /usr/bin/Xdcv -output 800x600+0+0 -output 800x600+800+0 -output 800x600+1600+0 -output 800x600+2400+0 -enabledoutputs 1 vt2 -displayfd 3 -auth /run/user/541001128/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -novtswitch -verbose 3 I'm also unable to reproduce the problem using xrdp + Xorg. While discussing this with the desktop crew, it was mentioned that we see the same problems in Xorg. And to a much lesser extent some issues in Wayland too when changing scales. mutter and gnome-shell versions being used: $ sudo apt-cache policy mutter-common mutter-common: Installed: 42.2-0ubuntu1 Candidate: 42.5-0ubuntu1 Version table: 42.5-0ubuntu1 500 500 http://sa-east-1.ec2.archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages *** 42.2-0ubuntu1 100 100 /var/lib/dpkg/status 42.0-3ubuntu2 500 500 http://sa-east-1.ec2.archive.ubuntu.com/ubuntu jammy/main amd64 Packages $ sudo apt-cache policy gnome-shell gnome-shell: Installed: 42.4-0ubuntu0.22.04.1 Candidate: 42.5-0ubuntu1 Version table: 42.5-0ubuntu1 500 500 http://sa-east-1.ec2.archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages *** 42.4-0ubuntu0.22.04.1 100 100 /var/lib/dpkg/status 42.0-2ubuntu1 500 500 http://sa-east-1.ec2.archive.ubuntu.com/ubuntu jammy/main amd64 Packages To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2020782/+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