So today I clicked ‘enable HDR’ on one of my monitors and something broke. The whole system froze up and the HDR monitor went black. If I reboot it freezes right after I login.

If I unplug that monitor or start in X11 instead of Wayland then everything is fine. Plugging the HDR monitor in while I’m logged into a Wayland session also freezes everything.

How can I disable the HDR setting? The monitor doesn’t show in System Settings whilst its unplugged so I’m hoping theirs some way to fix it on the CLI. The only place I’ve found HDR referenced is .config/kwinoutputconfig.json. I set HDR to false but after reboot it’s set to true again. I also tried deleting .config/kwinrc and .local/share/kscreen but no luck.

I’m fine with just resetting all Display settings if that’s required.

----- UPDATE ------

Bug report filed here: https://bugs.kde.org/show_bug.cgi?id=485403

Fixed by

  • Ctrl + Alt + F3 to go into terminal
  • Set HighDynamicRange and WideColorGamut to false in ~/.config/kwinoutputconfig.json
  • Execute plasmashell --replace
  • Reboot, Login, Reattach HDR Monitor

------ UPDATE ------

After updating and trying again today the steps above no longer worked. You still need to change ~/.config/kwinoutputconfig.json but plasmashell --replace no longer works for me.

Running killall kwin_wayland also just bumps me from my terminal back into the desktop. kwin can’t be running when you change that file or it will be overridden.

I booted into a separate Linux Live USB and change the files that way.

Thank you everyone for your help 🎉

    • RustmilianEnglish
      3•8 months ago

      Which one of these is the problem monitor? benq or gigabyte ?

      Edit : nvm, I see you already said Gigabyte.

    • RustmilianEnglish
      3•8 months ago

      Looking through the probe logs, and seeing that your monitor is using EISA bus and works fine without HDR, there doesn’t appear to be any issues on the Linux side of things. My guess is that they didn’t implement HDR on the monitors side exactly to spec and that’s where the problem resides. So, in this sense some monitor specific quirk fixup code is needed on the Linux side of things to get it working properly. If the devs ask any additional steps from you, be sure to do it and provide feedback.