https://bugs.freedesktop.org/show_bug.cgi?id=75992
--- Comment #8 from Alex Deucher agd5f@yahoo.com --- Created attachment 96460 --> https://bugs.freedesktop.org/attachment.cgi?id=96460&action=edit possible fix
(In reply to comment #7)
The only setting I cannot revert in the patch is:
pi->mclk_dpm_key_disabled = 1;
Thanks for narrowing it down. Does the attached patch help? Remove all previous patches when testing this.