G3 iBook LCD brightness in X under kernel 2.4.25 and 2.6.8
I'm trying to migrate from a 2.4 to a 2.6 kernel, but I have one last problem
keeping me with 2.4.25. There's a problem with adjusting screen brightness
under X (4.3.0.dfsg.1-8).
I'm running pbbuttonsd 0.6.6-2 with gtkpbbuttons 0.6.4-3 (which are tools that
enable the LCD to be dimmed and brightened with keyboard pressed). When I'm
running the Debian kernel-image 2.4.25-8 and I press the brightness up or
down keys, I get the on-screen indication from gtkpbbuttons and the LCD dims
or brightens as expected in both X and on the console. However, when I boot
into kernel-image 2.6.8-6 or 2.6.9-1 and press the brightness keys, I get the
on-screen indication in X, but the LCD doesn't change brightness. However, if
I switch to a VT with a console, the brightness changes to what I tried to
change it to. Also, pressing the brightness buttons works fine when I press
them while in the console.
My video card is a Mach64, and I'm using the 'ati' driver for X. One guess I
have is that in 2.6, lots more things are built as kernel modules. I'd like
to try build any needed video stuff in, but I don't know what it could be.
Does anyone here have an idea what controls screen brightness in X?
The reason this is important for me is that the LCD is not dimmed when I close
the lid for sleep, which kind of ruins the point of sleep.
Does anyone have an idea of what else I need to do to get screen dimming to
work under X with Linux 2.6?