Created attachment 85578 [details] [review]
disable various dpm features

I would suggest disabling various dpm features and see if you can narrow down
which, if any, help.  This patch disables just about everything.

ni_dpm_force_performance_level(rdev, RADEON_DPM_FORCED_LEVEL_AUTO) is what
actually sets the dynamic performance switching into motion.  Prior to that the
hw is locked into the low performance level.  I sounds like there is some bad
parameter that is causing a lock up when the smc enables state switching.

Separate from the patch can you also try changing the
ni_dpm_force_performance_level(rdev, RADEON_DPM_FORCED_LEVEL_AUTO) call in
ni_dpm_set_power_state() to low (RADEON_DPM_FORCED_LEVEL_LOW) or high
(RADEON_DPM_FORCED_LEVEL_HIGH) rather than auto?  See if you still get a lock
up.