[ltp] Changing backlight on X60s

[Damjan]

This is a report how backklight behaves on a X60s, intel 950 graphics,
kernel 2.6.25.3, tp-acpi 0.20-20080430, BIOS 7BETD2WW (2.13 )
intel 2.3.1 X driver, xorg server 1.4.0.90.

I have the acpi video module loaded.

Changing brightness with "xbacklight" will:
- change the screen brightness
- Kmilo will show a correct notification (which reads nvram IMHO)
- change the value in /sys/class/backlight/acpi_video1/brightness (but
  not acpi_video0)
- will NOT generate an ACPI event (acpi_listen)
- will NOT generate an input event  (input-events on "ThinkPad Extra Buttons"
  and both of the "Video Bus" event devices).

Via /sys/.../.../brightness
- Writing to any of acpi_video0 and acpi_video1 will change the
  brightness.
- Kmilo will show a correct notification
- xbacklight will NOT be updated
- writing to acpi_video0 generates an acpi "ibm/hotkey HKEY 00000080
  00005010" event, but any of the previous effects have a lag(*). 
- writing to acpi_video1 will NOT generate any acpi event, no lag.

Via Fn+Home/End
- change the screen brightness
- Kmilo will show a correct notification
- xbacklight will NOT be updated
- nither .../acpi_video1/brightness nor acpi_video0 will be changed
- generate "video LCD0 00000087 00000000" and "ibm/hotkey HKEY 00000080
  00005010" acpi events (*)
- generate an EV_KEY and EV_SYN event on one of the "Video Bus" devices
  (/dev/input/event4 in my case)
- there's a lag between pressing the buttons and any of the above
  effects (*)

(*) IMHO, the lag happens only when I first go to 0 backlight via Fn+End. Only
then I also get two acpi events. There seems to be no way of getting rid
of the lag but to reboot (tried reloading video and thinkpad-acpi
modules). This seems to be some kind of a BUG - does anyone know
anything about it?

What about the other inconsistences?

-- 
damjan | дамјан
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