So the problem is not the configuration but that for some reason the 
backlight state is set to off by default.


On Thu, 22 Feb 2007, David Miller wrote:

From: James Simmons <redacted>
Date: Thu, 22 Feb 2007 15:55:24 +0000 (GMT)

quoted

I just tested various confirations of backlight support. Backlight is 
ALWAYS selected by default when you select a particular fbdev driver that 
has backlight support. You just have the option to turn it off if you 
want. These problems are showing up because of stale .config files.

BTW, enabling the backlight option broke things for me with
Radeon on sparc64 too, FWIW.

And when the option was presented to me for the first time,
the default was yes, so that's what I gave it.

This is what a lot of users would see.