Going back to last year there has been work by AMD engineers on an experimental FreeSync video mode optimization to avoid screen blanking around full-screen video playback. Basically avoiding an entire mode-set when changing the timing mode during video playback to bypass any screen flickering/blanking. That work has now been updated to its sixth spin while it’s being viewed as a temporary measure until a better solution can be devised…

Source: Phoronix – AMDGPU FreeSync Video Mode Optimization Updated But Too Late For Linux 5.12