Light locker settings

This article is about the following Linux packages:

  • xset – the user preference command-line tool for X11, controlling screen blanking and monitor power management,
  • light-locker – the package for password locking screens, where lightdm is the desktop manager.
  • light-locker-settings – the GUI configuration tool for light-locker
  • xscreensaver – the popular screen saver program

light-locker-settings is a python program that can be used to set the screen saver and lock features associated with light-locker, the screen locker for lightdm.

When the “Apply” button is pressed in light-locker-settings, it writes the file ~/.config/autostart/screensaver-settings.desktop
containing the xset command to set the screen blanking and dpms poweroff timeouts.

If XScreenSaver is installed it runs a daemon that regularly re-write the xset values. Hence the light-locker settings will appear to revert frequently during a session if the xscreensaver process is running. If the display setting “Power Management Enabled” is un-ticked in XscreenSaver it will disable all DPMS power settings for the monitor.

The timeout values for screen blanking (“Screen Saver”) and DPMS can be seen by running:

xset q

Note that light-locker-settings sets DPMS values for Standby, Suspend and Off the same since LCD screens are used predominately now. Separate values for Standy, Suspend and Off are a legacy of CRT monitors.


  1. Light Locker Setting: Blank screen after: Never
  2. Set the same value for:
    1. Light Locker Settings – Switch off display after 20 minutes
    2. XScreenSaver – Standby, Suspend, Off: 20 minutes
  3. XScreenSaver:
    1. Blank after: 10 minutes
    2. Untick “Lock Screen After”

(Unfortunately there is still a lot of screen flickering as the monitor comes back on and switches between virtual terminals tty7 & tty8.