Thanks Simon, Looks like the KBCL variable is indeed the right one. Strange that it changed from 01 to 04 rather than 01 to 05 though... If you have time for a few more tests, I would love to know what values it takes when the UEFI variable is modified from 00 through 07.
Currently we have: UEFI KBCL 00 01 01 02 03 04 05 04 06 07 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-settings-daemon in Ubuntu. https://bugs.launchpad.net/bugs/1203592 Title: Keyboard backlight does not work in Samsung Series 9 NP900X4C Status in “gnome-settings-daemon” package in Ubuntu: Confirmed Bug description: In Ubuntu 13.04, the keyboard backlight does not work in Samsung Series 9 NP900X4C. Adding the FN key mappings as described in https://help.ubuntu.com/community/SamsungSeries9 does show information in the notification area when pressing the keyboard backlight's + and - buttons, but: 1) The notification always identifies the backlight as "full max" 2) It has no effect on the backlight - it's always off When I first installed Ubuntu on this machine (12.10), even though the fn keys never worked I did have intermitent backlight functionality - the light sensor would sometimes work and I'd see light in the keyboard. I dual boot in Windows 8 and backlighting works there, so this is not a hardware issue. More discussion can be found here: http://askubuntu.com/questions/233312/how-to-make-keyboard-backlight- fn-buttons-work-in-samsung-series-9 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/1203592/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

