https://bugs.freedesktop.org/show_bug.cgi?id=91880
--- Comment #120 from DesiOtaku tej.ashok.shah@gmail.com --- I hate to "me too" here, but I can confirm that the steps outlined in comment #115 does not resolve the problem. However, the power_dpm_force_performance_level and power_dpm_state trick outlined in comment #29 does prevent it from freezing.
I have a ASUS Radeon R9 390X running Kubuntu 16.04. I am willing to test out any potential fixes.