Bug#462190: xserver-xorg-video-ati: backlight control doesn't work with Radeon Mobility M9

[Alex Deucher]

On Jan 22, 2008 10:18 PM, Ingo Saitz <ingo at debian.org> wrote:
> Package: xserver-xorg-video-ati
> Version: 1:6.7.197~git20071219.ce4fa1ce-1
> Severity: normal
>
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> On my Compaq Evo N800w I can control the backlight with Fn-F7/Fn-F8.
> Upto version 1:6.7.196-2 this did work, for any later version it fails
> and those keys even cease to work in textmode until I do a reboot.
>
> Allversions after 1:6.7.196-2 have this bug, even those in experimental

backlight control is an oem specific mess.  In order to fix lid
support, we had do mess with some of the bios scratch regs.
Unfortunately, these changes seem to break backlight on some laptops,
but not others.  I plan to try and sort this out better in the coming
weeks, but unfortunately, a lot of this is oem specific so I don't
know that we will ever get a perfect solution.

Alex