I recently installed ubuntu 13.04 (kernel 3.8.0.y) on an older Asus UL30vt laptop. This is a switchable graphics (optimus) laptop with a intel onboard graphics card and an Nvidia Geforce G210M. I am running bumblebee on the laptop, so the active graphics card is the intel one.
All other fn keys work, but only the volume-up and volume-down keys bring up the on-screen display.
There are a variety of Linux help pages for this laptop online (including https://wiki.ubuntu.com/AsusUL, http://wiki.daviddarts.com/Ubuntu_Lucid_on_the_Asus_UL30VT#Screen_Brightness, https://wiki.debian.org/InstallingDebianOn/Asus/UL30VT) but they seem to rely on scripts that don't exist anymore. For example, as far as I know, the asus-wmi dkms modules were included in kernel 3.8 and should not be necessary.
I am unable to adjust the backlight using
xbacklight -set X
where X is a value between 0 and 100. The command runs without complaints, using e.g. xbacklight -set 0, but the backlight intensity does not change.
I have tried a variety of grub boot parameters, including testing all of the following in turn:
acpi_osi=, acpi_osi=Linux, acpi_osi='!Windows2012', acpi_backlight=vendor,
but with no improvement. I also tried using both acpi_osi=Linux and acpi_backlight=vendor at the same time, with no improvement.
Thus far, I have only found one way to change the screen backlight:
sudo setpci -s 00:02.0 F4.B=XX
where XX is a value between 1a and ff (hexadecimal).
I have found a linux kernel note that there is a change in a new kernel related to this laptop and the backlight: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c8f6d8351ba8c89d5cd4c562552ec7ec29274e31 However, this code forces the vendor driver, which might be the same as using acpi_backlight=vendor which did not work.
I'd appreciate any help.