[ltp] Bug#448467: xserver-xorg-video-intel: Thinkpad brightness keys don't work

[Marcus Better]

Package: xserver-xorg-video-intel
Version: 2:2.1.1-4
Severity: normal

The brightness control keys on my Thinkpad R60 stopped working in X
some time ago. I have probably upgraded both kernel and X.org since
then, and don't know exactly when it broke.

Pressing the keys in an X session now only causes a short flicker, but
does not affect the brightness. However the KDE on-screen display
seems to think everything is fine since I can control the level it
reports.

The brightness keys still work in a virtual console, just not in X.

"xbacklight -set" changes the brightness in a totally random way. For
example p=98 is barely visible, and most other settings give a
constant medium-bright level.

I can control the brightness at least reasonably well with
  echo 50 > /sys/devices/virtual/backlight/acpi_video1/brightness
except that levels below 30 don't seem to have any effect.

Also I can do
  echo up > /proc/acpi/ibm/brightness
or
  echo down > /proc/acpi/ibm/brightness

I have an unpatched kernel 2.6.23 (Linus' git tree) with thinkpad-acpi
0.16, hal 0.5.9.1-6, acpid 1.0.4-7.1.

The problem matches this description [1] which points to a fix in Ubuntu.

[1] http://permalink.gmane.org/gmane.linux.hardware.thinkpad/32463

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.23-melech (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=sv_SE.UTF-8, LC_CTYPE=sv_SE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages xserver-xorg-video-intel depends on:
ii  libc6                         2.6.1-1    GNU C Library: Shared libraries
ii  libdrm2                       2.3.0-4    Userspace interface to kernel DRM 
ii  xserver-xorg-core             2:1.4-3    Xorg X server - core server

xserver-xorg-video-intel recommends no packages.

-- no debconf information