Bug#754200: kde-baseapps-bin: KDE fails to recognize keyboard backlight capabilities on fresh boot

[Andres Cimmarusti <acimmarusti@gmail.com>]

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