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After manually setting the display brightness on my laptop, the system re-sets the value. If the laptop is plugged in, the value is set to full brightness; if it is not plugged in, it is set to dimmer. How do I stop that behavior?

Note that I am not talking about what it does in response to the event of plugging in or unplugging my system. It changes on it's own - usually several minutes after I change the brightness value. I have observed this behavior on different systems, different distributions, and different desktop environments.

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That behaviour is usually controlled from the systems Power Management/Power Saving settings. How to access that depends on your flavour of linux and/or desktop system (Gnome or KDE for example)

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Yeah, I've looked there in both Gnome and KDE to no avail. I'm hoping someone knows how to deal with ACPI in Linux at a lower level. – Shawn J. Goff Mar 16 '10 at 12:00

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