[ltp] X300 Debian 5

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Wed, 8 Jul 2009 14:06:48 -0300

On Wed, 08 Jul 2009, Gregor Rolshausen wrote:
> did anyone manage to run Volume & Brightness (hotkey) control in
> Debian Lenny (KDE)?

Thinkpad-acpi won't do it for you. You need an X server that can do it, you
need HAL doing it, and you need ACPI video working fine (I call this the
"Intel OpRegion plague".  I.e. it is supposed to be outside thinkpad-acpi's

You can coax thinkpad-acpi to control brightness for you, but that's not the
way things should work, and you can crash the X server if it decides it
doesn't like the BIOS changing GPU registers behind its back.

1. use HAL to enable the KEY_BRIGHTNESS_UP/DOWN hotkeys in thinkpad-acpi
(scan codes 0x0f and 0x10), and enable the required bits in thinkpad-acpi's
hotkey_mask attribute (refer to the documentation).

2. load acpi video in "vendor" mode - see kernel documentation

3. Have whatever listens to KEY_BRIGHTNESS_UP/DOWN in userspace call back
into thinkpad-acpi's backlight control.

And only do this in Lenovo laptops.  Never do it on IBM ones, they don't
need it and you will break things or reduce the lifetime of your CCFL.

I am writing a patch to streamline the above, as in "thinkpad-acpi will
autoconfig when acpi-video is loaded in vendor mode".

  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh