Ubuntu手动实现显示屏背光调节

强制手工调节方式
Sony VPCEA28EC设置自动背光调节

Ubuntu 9.04版时，SONY笔记本不能调节背光，通过修改/proc/acpi/video/VGA/LCD/brightness数值来调节背光，并通过acpi/events绑定热键。

强制手工调节方式

cat /proc/acpi/video/VGA/LCD/brightness
echo 70 |sudo tee /proc/acpi/video/VGA/LCD/brightness

Sony VPCEA28EC设置自动背光调节

设置热键绑定

cat > /etc/acpi/events/sony-brightness-down <<EOF
event=sony/hotkey (SPIC|SNC) 00000001 00000010
action=/etc/acpi/sony-brn-updown.sh down
EOF

cat > /etc/acpi/events/sony-brightness-up <<EOF
event=sony/hotkey (SPIC|SNC) 00000001 00000011
action=/etc/acpi/sony-brn-updown.sh up
EOF

调节脚本：/etc/acpi/sony-brn-updown.sh

#!/bin/sh
#levels:  5 8 11 16 23 34 48 70 100
#current: 70

current=`cat /proc/acpi/video/VGA/LCD/brightness |grep current|awk '{print $2}'`
#echo "current=$current" #>>/tmp/test
new=100
case "$current" in
5)
    [ "$1" = "down" ] && new=5 
    [ "$1" = "up" ] && new=8
    ;;
8)
    [ "$1" = "down" ] && new=5
    [ "$1" = "up" ] && new=11
    ;;
11)
    [ "$1" = "down" ] && new=8
    [ "$1" = "up" ] && new=16
    ;;
16)
    [ "$1" = "down" ] && new=11
    [ "$1" = "up" ] && new=23
    ;;
23)
    [ "$1" = "down" ] && new=16
    [ "$1" = "up" ] && new=34
    ;;
34)
    [ "$1" = "down" ] && new=23
    [ "$1" = "up" ] && new=48
    ;;
48)
    [ "$1" = "down" ] && new=34
    [ "$1" = "up" ] && new=70
    ;;
70)
    [ "$1" = "down" ] && new=48
    [ "$1" = "up" ] && new=100
    ;;
100|*)
    [ "$1" = "up" ] && new=100
    [ "$1" = "down" ] && new=70
    ;;
esac
#echo "new=$new" #>>/tmp/test
[ "$new" != "$current" ] && echo "$new" > /proc/acpi/video/VGA/LCD/brightness
exit 0

启用

sudo chmod +x /etc/acpi/sony-brn-updown.sh
sudo /etc/init.d/acpi-support restart
sudo /etc/init.d/acpid restart