Ubuntu

Comment 7 for bug 224636

Here is workaround for M50Sv and maybe other laptop controled by asus-laptop driver

This is compilation from http://bbs.archlinux.org/viewtopic.php?id=38935
Copy files from attached file to corresponding directories

Enables ASUS Light Sensor switching
/etc/acpi/events/asus-ctrl-a
/etc/acpi/asus-ls-switch.sh

Brightness control scripts (working with ASUS Light Sensor enabled)
/etc/acpi/asus-brn-up.sh
/etc/acpi/asus-brn-down.sh

Script that saves settings for ASUS Light Sensor
/etc/init.d/asus-ls
/etc/asus-ls.conf

run
sudo update-rc.d asus-ls defaults

and
sudo /etc/init.d/acpid restart

If Brightness down key doesn't work
change first line of /etc/acpi/events/asus-brightness-down
to this
event=hotkey ATKD 0000002[0123456789abcdef]

Sorry for my English