https://bugs.freedesktop.org/show_bug.cgi?id=109359
--- Comment #5 from Timur Kristóf venemo@msn.com --- (In reply to keziolio123 from comment #4)
I have the same issue with an RX480 if i set amdgpu.ppfeaturemask=0xffffffff (for overclocking), without any command line changes there is no flickering
That's because when you overclock, your clock speed gets high enough so that flickering doesn't happen.