Here are my experiments with using the back-light of my R580.
I first reported them in the thread viewtopic.php?p=3686#p3686
but I think it is now better to create a dedicated thread :-)
To summarize, I've installed Kubuntu 64bits, enabled the nvidia proprietary driver and installed the packages provided by "Linux On My Samsung". To be able to control the BL with the Fn-Up & Fn-Down keys, I found the following workaround:
- install the samsung-backlight package (once)
- rmmod the module when logged-in.
As suggested by voRia, I have created the following script in ~/.kde/Autostart/ to automatically apply the rmmod:
sudo -n /sbin/rmmod samsung_backlight
And added the following line at the end
michel ALL=NOPASSWD:/sbin/rmmod samsung_backlight
To avoid touching the sudoers, I tried to add the rmmod commands to all files in /etc/kde4/kdm/. But it never worked: the module was removed but the Fn keys didn't work. Very strange.
I'll post follow-ups to this when I have time to experiment (after a while, I'm bored to reboot all the time)