https://bugs.freedesktop.org/show_bug.cgi?id=81644
--- Comment #114 from Alexandre Demers alexandre.f.demers@gmail.com --- (In reply to comment #113)
I commented out every "return ret;" of si_dpm_set_power_state() in si_dpm.c. After booting this modified kernel, I can confirm this is the only error reported in si_dpm_set_power_state(): every other verification passes OK and it goes down to the very end.
Oops, I had too many bugs opened, I wrote this comment in the wrong one.