Thanks a lot @ Brandon Wright, your patch really does the trick. I also totally agree on your opinion that it should be mainlined as at least a temporary solution (and also get backported to older kernels). I just noticed that it works fine with xf86-video-amdgpu driver, but with modesetting driver, xorg or the driver freezes when starting/logging in. Not sure if this is related to latest 4.21-wip-changes or the cursor patch though.