[arch-general] thinkpad t61 and not able to adjust brightness

[Sergey Manucharian]

On Fri, 17 Apr 2009 09:47:38 -0400
Adam Stokes <adam.stokes at gmail.com> wrote:

> Thanks for the information, I did add those keycodes to my .Xmodmap
> with no change unfortunately. I also installed the acpi/acpid packages
> but I haven't actually rebooted yet since it seems that acpid will not
> run due to some devices being in use at the moment.
> 
> If there are anymore ideas I would like to hear them.

When long time ago I had a similar problem I've added the
following into the main "case" structure in "/etc/acpi/handler.sh":

---------------------------8<-------------------------------
video)
   case "$2" in
   LCD0) case "$3" in
         00000086) /usr/local/bin/brightness_up ;;
         00000087) /usr/local/bin/brightness_down ;;
                *) logger "LCD0 button undefined: $1 $2 $3 $4" ;; 
         esac ;;
   *) logger "Video button undefined: $1 $2 $3 $4" ;; 
   esac ;;
---------------------------8<-------------------------------
I really don't remember what "00000086" and "00000087" stand for.
The brightness changing scripts are below.

"/usr/local/bin/brightness_up":
---------------------------8<-------------------------------
#!/bin/bash
# LCD brightness up
declare -i BRIGHT
let BRIGHT=`cat /sys/class/backlight/acpi_video0/actual_brightness`+1
if [ "$BRIGHT" -gt 15 ]; then
  BRIGHT=15
fi
echo $BRIGHT > /sys/class/backlight/acpi_video0/brightness
---------------------------8<-------------------------------

and "/usr/local/bin/brightness_down":
---------------------------8<-------------------------------
#!/bin/bash
# LCD brightness down
declare -i BRIGHT
let BRIGHT=`cat /sys/class/backlight/acpi_video0/actual_brightness`-1
if [ "$BRIGHT" -lt 0 ]; then
  BRIGHT=0
fi
echo $BRIGHT > /sys/class/backlight/acpi_video0/brightness
---------------------------8<-------------------------------

Cheers,
Sergey