With the help of someone in the KDE forums () I found out the problem is the upower daemon is not started by KDE early enough (before KDM login) and this causes KDE power manager to become unaware of the keyboard brightness option.
I tested this by in the following way: 1. Reboot machine 2. Wait till KDM login screen 3. Switch to a VT 4. Login there 5. ps aux | grep upower → zero results → upower is not running before login 6. invoke the command in my previous post to changer keyboard brightness 7. Upowerd is forced to start by dbus 8. Log out from VT 9. Login to KDE 10. Keyboard brightness works as expected It looks like upowerd is working as expected (from reading its description on its man page). It falls to the desktop environment to probe it and recognize that's possible to changer the keyboard backlight brightness. Andres -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org