Filtering on GPU is a bad idea because I think there is also computers with nvidia chip and correct acpi implementation.
You're right for num_levels. I have the same problem of brighness going to 0 then going to the right brightness. It seems to be a gnome-power-manager bug (I don't have this bug on previous version, and I just reinstalled my patch on my Feisty). If you are interested, I have debug trace of the instructions send to hal by gnome-power-manager (you can see it by yourself by sudo killall hald sudo hald --daemon=no --verbose=yes ) => there is a lot of brightness update starting from 0 value. -- LCD brightness setting doesn't work with Sony Vaio VGN-S5M https://launchpad.net/bugs/77739 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs