https://bugs.kde.org/show_bug.cgi?id=485269
Bug ID: 485269 Summary: 'Unifying output' leaves the system with no display output Classification: Plasma Product: KScreen Version: 6.0.3 Platform: Other OS: Linux Status: REPORTED Severity: major Priority: NOR Component: common Assignee: kscreen-bugs-n...@kde.org Reporter: shaloksha...@protonmail.ch Target Milestone: --- SUMMARY I had a TV connected to my laptop, and chose only it as the shown output. Then I hit Fn + F7 to open the screen layout widget, and chose "Unify output". The result was a black screen on both the laptop and the TV. Removing the cable connection, was not restoring the display output on the laptop. Rebooting booted straight into a black screen as well. I booted into my second installation (first is KaOS, second NixOS) and tried the same thing there again, with the same outcome. This has to be due to a recent change, as I use both systems on a rolling release, and had used that feature in the past with the same hardware, and no such issue occurred. In this case, no user error was involved. Still, I managed to reach a similar bad state (with only the TV being inaccessible) with a bad configuration, that involved me confirming a display resolution for the TV as valid, that wasnt. In both cases, the simple usage of a multi monitor setup meant partly, or complete loss of display functionality. To make matters worse, kscreen is not a declarative file anymore. I think that is a very big mistake, and I strongly suggest to restore that functionality. Today, it seems that the entire display configuration is created by a binary, that then creates a yaml file. That one cannot be edited and reloaded. This goes against the UNIX philosophy and makes it very hard to restore from such a case. I would need to do dark magic, or have a rollback feature on filesystem level enabled, to recover from this. I thought about several mechanisms to prevent such issues. 1) Ask if the configuration is fine for the 'Screen Layout' widget as well. At least when the configuration involves new settings. Maybe when the API and/or hardware changes. 2.) Implement a shortcut, that resets the configuration to its default state. 3.) Implement such a button to reset the configuration in the KScreen KCM. This could have helped with the second case, where only the external display was inaccessible. I put this on major, and think it could be ranked more severe even. STEPS TO REPRODUCE 1. 2. 3. OBSERVED RESULT EXPECTED RESULT SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION -- You are receiving this mail because: You are watching all bug changes.