LCD brightness issue

I've installed archlinux on my laptop, everything works well except the brightness control.
The screen originally has 11 brightness levels, but when I either press Fn+F6/F7 key or use gnome-power-manager to adjust brightness, it always skips a level.
/proc/acpi/video/VGA/LCD/brightness
levels: 100 60 20 28 36 44 52 60 68 76 84 92 100
current: 100
I can only get level 20 36 52 68 84 and 100
The problem also exists in console mode.
I tried adding video module to blacklist, then brightness cannot be adjusted at all.
However, I never get this problem in openSUSE, all 11 levels are available.
Could anyone help me? Thanks!:|

http://forums.nvidia.com/index.php?show … t&p=386303
Hmmm...I found this on the nvidia forums:
I have a Samsung R700 laptop and my brightness stopped working after installing the restricted drivers. This is how I fixed it.
Press Ctrl-Alt-F1 to get a virtual console. Once you are in this console I think different video drivers are active so the following worked for me to adjust brightness.
Logged in and ran the following command:
echo -n 70 > /proc/acpi/video/NVID/LCD/brightness
then logged out and pressed Ctrl-Alt-F7 to go back to X
It's possible your brightness key on your laptop may work straight after you press ctrl-alt-f1 and you won't have to login and do the acpi stuff.
Also I have a startup script to set my brightness to a fixed value before X starts. It's not ideal but it's the only solution I could find that worked for me until the drivers are fixed!
Hope this helps.
Last edited by kclive18 (2008-07-08 11:19:25)

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  • Laptop mode lowers LCD brightness when on AC [SOLVED]

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