I have similar problem with AMD graphics Renoir (Is it the same problem as this issue #1870736 ?). I can scale display from 100% to 200%, but scaling to 125% or 150% fails (see log below). At least I'm able to scale text to 1.25.
syslog: ------- Aug 15 18:36:47 yoga gnome-shell[9538]: Impossible to set scaling on crtc 925 to 0,625000, error id 2 Aug 15 18:36:47 yoga gnome-shell[9538]: Window manager warning: Scalig CRTC 925 at 1,000000 failed Used HW/SW: ----------- * Lenovo Yoga Slim 7 14ARE05 (Ryzen 4700u, Integrated AMD Radeon Graphics), * Ubuntu 20.04.1 $ lspci 03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Renoir (rev c2) Kernel modules: amdgpu $ xrandr xrandr: Failed to get size of gamma for output default Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080 default connected primary 1920x1080+0+0 0mm x 0mm 1920x1080 77.00* -- 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/1870736 Title: [nvidia] Screen scaling 125% gives 200% Status in gnome-control-center package in Ubuntu: Confirmed Status in mutter package in Ubuntu: Confirmed Bug description: Procedure used: 1. Fully updated system via apt update && apt upgrade 2. Select the screen setup in gnome control center 3. Click the "Fractional scaling" toggle 4. Select 125% and click the green "use" button top right (it says "Anvend" in dansih) 5. Observe that the window has grown a lot, click the "use new settings" button 6. The window tells me, I am at 200% scaling. The "200%" option is now highlighted. 7. Switch back to 100% and file this bug. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: ubuntu-release-upgrader-core 1:20.04.16 ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27 Uname: Linux 5.4.0-21-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu22 Architecture: amd64 CrashDB: ubuntu CurrentDesktop: ubuntu:GNOME Date: Sat Apr 4 09:42:34 2020 InstallationDate: Installed on 2018-01-14 (810 days ago) InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801) PackageArchitecture: all ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=da_DK.UTF-8 SHELL=/bin/bash SourcePackage: ubuntu-release-upgrader Symptom: release-upgrade UpgradeStatus: Upgraded to focal on 2020-04-03 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1870736/+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