https://bugs.freedesktop.org/show_bug.cgi?id=106175
--- Comment #73 from tempel.julian@gmail.com --- Yeah, I'd be extremely disappointing if this wouldn't land before linux 4.21 DRM merging window closes. Like I already said, I think this is even worth getting backported to older kernels, as I'd consider it an important fix. Likely every AMD Xorg user has degraded performance because of this.