Comment 9 for bug 516354

@WindPower: This isn't relevant, since you installed both drivers nvidia-bl-dkms and mbp-nvidia-bl-dkms. (If you didn't install the latter from the mactel repo, the version provided by the linux kernel should also have been sufficient.) However, until nvidia-bl 0.15.0 nvidia-bl didn't auto-load. mbp-nvidia-bl always does. So, if you added a line to /etc/modules for nvidia-bl, you ended up loading both drivers providing two interfaces in /sys/class/backlight. Furthermore, if the brightness keys didn't work, HAL has just used the wrong interface.

As of nvidia-bl version 0.15.1, I got auto-loading to work. That also means the package now installs a file in /etc/modprobe.d, that blacklists mbp-nvidia-bl. That's why your scripting approach doesn't work anymore - the driver you used is just missing.

Finally, for some strange reason nvidia-bl doesn't work on some MacBook Pro 5 models. Probably those incorporating two graphics adapters. But due to a lack of information, I don't really know.

That means, if you can confirm that nvidia-bl doesn't work (as you did), just deinstall it. There's no reason to have both drivers installed. Unfortunately, mbp-nvidia-bl is also known to not work on some Apple machines. That's why there are both in the repos.

Btw: They aren't completely redundant. While nvidia-bl (in theory) should support a wide range of machine incorporating Nvidia graphics adapters (not just from Apple), does mbp-nvidia-bl only work on Apple machines. In contrast to his name, not just MacBook Pros with Nvidia graphics, but all models incorporating Intel processors.