So now that I have been using Red Hat for a few weeks as my primary desktop, there have been lots of little things that are annoying. Working through a few of them now, one is that putting my laptop to sleep (which works fine out of the box) and I can awake from hibernate fine but the brightness controls are out of whack, as other users have identified in the Lenovo forums¹. Also noticed that users on other platforms see the same thing², so it is a hardware/driver issues since this can be done via the nvidia-settings³ command.

Based on the ThinkWiki⁴ site other users have gotten this working, and based on the guidance from the Ubuntu users. Unfortunately there is no easy way to do this via a tool, so you just need to hack at your xorg.conf file… not my favorite method since I quickly forget and lose these changes during upgrades.

...
Section "Device"
        Identifier  "Device0"
        Driver      "nvidia"
        VendorName  "NVIDIA Corporation"
# http://askubuntu.com/questions/76081/brightness-not-working-after-installing-nvidia-driver
        Option "RegistryDwords" "EnableBrightnessControl=1"
EndSection
...

Now logout or restart X and you should be able to use your regular brightness applet or in my case the ThinkPad buttons to control the brightness as expected.

Reference: