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portix

Member

Registered: 2009-01-13

Posts: 757

Prevent x-server setting display brightness

Hi,
i have a laptop with a ati radeon hd 4200 and i'm using the catalyst driver. I have also laptop-mode-tools installed to adjust the display brightness which works fine but every time the x-server is started the brightness is set to 100% so the brighness adjustment of laptop-mode-tools is quite useless, because it is set before the x-server is started.
My question is, is there a way to prevent the x-server setting the display brightness?

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dwb

stqn

Member

Registered: 2010-03-19

Posts: 1,191

Website

Re: Prevent x-server setting display brightness

Everytime I've had problems with something changing the brightness, it was gnome-power-manager. But I'm sure KDE (or even Xfce?) has the same terrible default behaviour.

portix

Member

Registered: 2009-01-13

Posts: 757

Re: Prevent x-server setting display brightness

I have neither gnome nor another DE installed, just X with dwm. It seems that the brightness is set by X. The workaround i am using now is

if [ "$(< /sys/devices/platform/smapi/ac_connected)" = 0 ]; then 
  xbacklight -set 17%
else 
  xbacklight -set 40%
fi

in my .xinitrc.

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dwb