graphics card issue with HP laptop running ubuntu 14.04 dimming function not working

Bought an HP laptop that came with windows 8.1. Changed the OS to Ubuntu 14.04 exclusively. Everything works great except for the screen dimming function no longer works. This laptop has an AMD processor and I believe also has an AMD Gallium graphics card if I remember correctly. I was not able to find any real fixes for this problem in the Ubuntu forums. I assume that once this computer gets a little older an update may fix it or a newer LTS version of Ubuntu may fix it? Can anyone do a driver update for this problem?