Benjamin Gaignard posted version 5 of his zpos per plane property patches to the dri-devel and linaro-mm-sig lists.
The patch history includes:
rebased on drm-next where Documentation/DocBook/gpu.tmpl doesn’t
rework sti patch because some plane functions have changed since v4
make sure that normalized zpos value is stay in the defined property
range and warn user if not.
Fix NULL pointer bug in rcar-du while setting zpos value.
No changes in the other drivers.
use kmalloc_array instead of kmalloc.
Correct normalize_zpos computation (comeback to Mareck original code)
add a zpos property into drm_plane structure to simplify code.
This allow to get/set zpos value in core and not in drivers code.
Fix various remarks.
refactor Marek’s patches to have per plane zpos property instead of only
one in core.
The patches can be found at : http://www.spinics.net/lists/dri-devel/msg112347.html