https://bugs.freedesktop.org/show_bug.cgi?id=102646
--- Comment #40 from tempel.julian@gmail.com --- Still having this issue with 2560 x 1440 @ 75Hz and latest 4.21-wip kernel. Manually forcing a single VRAM clock state eliminates the flicker artifacts. As soon as there is dynamic VRAM clocking happening, it flickers.