Comment 116 for bug 311716

The Fn-keys don't work for me on a Lenovo X300 with linux-image-2.6.27-11-generic (intrepid). Changing throuhg guidance-power-manager in kde4 works, though. I realized that pressing the Fn-keys for brightness up and down changes the value of /proc/acpi/video/VID/LCD0/brightness instead of /proc/acpi/video/VID1/LCD0/brightness (VID instead of VID1). Manually changing the latter (echo 80 > /proc/acpi/video/VID1/LCD0/brightness) does change the brightness. This is also reported for arch linux (see http://wiki.archlinux.org/index.php/Lenovo_Thinkpad_X300#Backlight) so it might not be ubuntu-specific.

I have in /etc/modprobe.d/options
options thinkpad_acpi experimental=1 fan_control=1 brightness_enable=1

and tried withouth all these options, and with
options video acpi_backlight=vendor

always same behaviour. I also tried with a new kernel with
# CONFIG_THINKPAD_ACPI_VIDEO is not set
(read somewhere, that that could help, but it didn't).

I just installed ubuntu intrepid on that notebook, so I can't say, under which constellation exactly it worked, but I remember, that the keys worked when I first installed intrepid from the CD, before updating. But it didn't work with the 2.6.27-7-kernel, which I tried to boot as well.

Should I open a new bug for that?

Ben