I'm using NixOS with KDE Plasma, Plasma Login Manager, and a ThinkPad X1 Carbon connected to an external monitor. I want the built-in display to remain off while the laptop is closed and the external monitor is used as the only screen. Although the display switches correctly at first, the internal panel turns back on after a few minutes. I tried configuring logind to ignore lid events and also enabled the Lenovo ThinkPad hardware module, but the behavior persisted. What configuration keeps the laptop reliably in clamshell mode?
1 Answer
Make sure the logind settings use the exact option names and then configure KDE’s power-management settings separately. A setup like this should prevent logind from reacting to the lid switch: services.logind.settings.Login = { HandleLidSwitch = "ignore"; HandleLidSwitchExternalPower = "ignore"; HandleLidSwitchDocked = "ignore"; LidSwitchIgnoreInhibited = "no"; }; After rebuilding and restarting, check KDE’s Power Management settings and set the lid-close action to do nothing as well. KDE can otherwise react to the lid independently and turn the internal panel back on.
This can be especially noticeable under KDE on Wayland, where the desktop power manager may override or compete with logind. If the display still wakes, verify that KDE’s lid action is disabled and that no separate power-management service is handling the event.