I have a Toshiba portege. Since some time I try to enable the backlit function but without success. I found several posts that should solve it, for example:
but it didn't work for me (although now I can set the screen brightness!). I have LTS 12.04. My /etc/rc.local is here:
setpci -s 00:02.0 F4.b=00 exit 0
GRUB_DEFAULT=0 GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor" GRUB_CMDLINE_LINUX="acpi_osi=Linux"
Thank you for your comments and help!