changing screen brightness broken in Xubuntu (12.04 and 14.04)

[Liviu Andronic]

Dear all,
For several releases now (12.04 and 14.04) and across several machines
(Lenovo 32-bit and Dell 64-bit), changing brightness settings is
broken. It doesn't work whether I use the laptop buttons to modify
screen brightness (to get the notification changing the percentage,
but actual brightness NOT move one bit) or the Brightness panel-plugin
from xfce4-power-manager (nothing really happens).

Is this a known issue (or should I report it to Launchpad)? But more
importantly, how can I change screen brightness in Xubuntu (install
gnome-power-manager, etc.)?

Regards,
Liviu

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