I had the same problem for about a month. I just bumped into the good news now: AMD Rolls Out AMDGPU-PRO 16.40 Driver for Ubuntu and Red Hat Enterprise Linux
For some reason couldn't manage to install it though! :/ :/
I installed drivers on ubuntu 16.04 but I stuck on the login screen. After uninstalling it, I am able to log in again. Is there any solution for this problem?