I have installed Lubuntu on my Dell Chromebook 11 and everything works except for the backlight. Can't set the backlight with the brightness keys, neither with xbacklight,xdotool or any other GUI tool.
I tried with a combination of grub options like
acpibacklight=vendor acpiosi= and
acpibacklight=legacy acpiosi= without success. Even more strange is that /sys/class/backlight/ is empty.
dmidecode - http://pastebin.com/hBJxuVvY
grep -r . /proc/acpi) - http://paste.ubuntu.com/9880798/
acpidump - paste.ubuntu.com/9880816/
fwts) - paste.ubuntu.com/9880883/
dmesg | grep 'ACPI: Video') - paste.ubuntu.com/9880928/
cat /proc/version) - paste.ubuntu.com/9880942/
Does that give any useful information on the issue?
Given that the VGA Graphic hardware is at the addres
00:02.0 I tried to set its register values manually like this
setpci -s 00:02.0 F4.B=30 without success as the backlight stays the same. Shouldn't this work on every device given that it interfaces directly to the hardware?