On Fri, Sep 6, 2019 at 4:45 PM Daniel Vetter daniel.vetter@ffwll.ch wrote:

We forgot that.

Proof is the one igt testcase we have:

https://gitlab.freedesktop.org/drm/igt-gpu-tools/blob/master/tests/kms_atomi...

While at it also document that we have immutable zpos properties in some cases.

Reported-by: Pekka Paalanen pekka.paalanen@collabora.com Cc: Pekka Paalanen pekka.paalanen@collabora.com Reviewed-by: Pekka Paalanen pekka.paalanen@collabora.com Cc: Ilia Mirkin imirkin@alum.mit.edu Acked-by: Ilia Mirkin imirkin@alum.mit.edu Signed-off-by: Daniel Vetter daniel.vetter@intel.com

From irc: Reviewed-by: Daniel Stone daniels@collabora.com

---

drivers/gpu/drm/drm_blend.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 37ac168fcb60..d02709dd2d4a 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -130,7 +130,12 @@

• Z position is set up with drm_plane_create_zpos_immutable_property() and
  

• drm_plane_create_zpos_property(). It controls the visibility of overlapping
  

• planes. Without this property the primary plane is always below the cursor
  

• • plane, and ordering between all other planes is undefined.
    

• • plane, and ordering between all other planes is undefined. The positive
    

• • Z axis points towards the user, i.e. planes with lower Z position values
    

• • are underneath planes with higher Z position values. Note that the Z
    

• • position value can also be immutable, to inform userspace about the
    

• • hard-coded stacking of overlay planes, see
    

• • drm_plane_create_zpos_immutable_property().
    

  • pixel blend mode:

  • Pixel blend mode is set up with drm_plane_create_blend_mode_property().
    

-- 2.23.0