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Old 04-07-07, 04:25 AM   #1
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Join Date: Apr 2007
Location: Germany
Posts: 8
Default Laptop Brightness Control


I'd like to get the brightness hotkeys on my laptop to work correctly, but there's no documentation available. :-(

Adding the following option to the nvidia kernel module makes the hotkeys work in X:

but there are a few problems (I'll use + for the "increase brightness button" and - for the "decrease brightness button"):
1. There's one step too much at the highest brightness. I.e. if I keep + pressed until the brightness does not increase anymore and then press - nothing happens. Pressing - a second time the brightness decreases. + increases, + no change, - no change, - decreases...
2. Using - I can lower the brightness until the backlight is completely off. But the lower brightness settings have the left side of the screen darker than the right side.
3. Using NVreg_PanelBrightnessLimits=60000 I was able to limit the lower brightness levels so that it doesn't shut off the backlight completely (the Fn+Backlit hotkey is what I want to use for that). Is there any documentation for the number for PanelBrightnessLimits available? If not, can I have an explanation please? I have only found out so far that using small numbers will make the +/- buttons useless again.

BTW: This is a Samsung R65 with a GeForce Go 7400 using 1.0-9755
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