Created attachment 1246221 [details]
Complete journalctl output
Description of problem:
After updating to kernel 4.9.6, performance of my Radeon (using free radeon driver) dropped drastically. When booting to previous 4.9.5, it works OK.
I've looked to journalctl and found this error:
kernel: [drm:si_dpm_set_power_state [radeon]] *ERROR* si_restrict_performance_levels_before_switch failed
There was also mesa update coming with that kernel update, but I have no idea if that has anything to do with it.
Got fixed by "itself" with next kernel update.