In discussion with adrian@ and zeising@, there appears to be a regression with suspend and resume on the Lenovo X1 Carbon first generation (i7-3667U).
With the packages drm-kmod, xorg, xfce, and xfce4-goodies, the system will successfully suspend and resume once, but on subsequent resumes gives a block in the top left corner of the screen and a frozen cursor. Pressing the power button will perform rc.shutdown routines.
xorg without startxfce4 appears to work correctly, and a similarly-configured T430 with only Intel graphics works correctly.
Issue is reproducible with both UEFI and BIOS/Legacy boot.
Please advise what additional information would help.