https://bugs.freedesktop.org/show_bug.cgi?id=106175
--- Comment #92 from tempel.julian@gmail.com --- This is the commit with which the stutter is introduced: https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu/commit/0d60233d...
(But it seems amdgpu.dc=1 unfortunately is also a bit more vulnerable towards stutter in general when new windows occur, compared to the old display stack.)