Comment # 9 on bug 73067 from Vasco Almeida

Yes, the attached patch fixed the flicker. Screen does not flick whichever
value is power_dpm_state or power_dpm_force_performance_level.

Before the patch, the flicker happened when switching from
power level 2    sclk: 66500 mclk: 95000 vddc: 1082
to
power level 1    sclk: 50000 mclk: 70000 vddc: 1046

In the way level 1 -> level 2 there is not screen flicker.