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authorDmitry Torokhov <[email protected]>2020-01-10 14:56:04 -0800
committerDmitry Torokhov <[email protected]>2020-01-10 14:56:04 -0800
commit1bdd3e05a0a3b4a97ea88bc46fef8fb265c8b94c (patch)
tree2244894a9ea0c941a8f32e5f3d196b4ea0eae24b /drivers/gpu/drm/drm_blend.c
parent643dd7416649bea2e8c61d8fdeeefb409a0ca5eb (diff)
parentc79f46a282390e0f5b306007bf7b11a46d529538 (diff)
Merge tag 'v5.5-rc5' into next
Sync up with mainline to get SPI "delay" API changes.
Diffstat (limited to 'drivers/gpu/drm/drm_blend.c')
-rw-r--r--drivers/gpu/drm/drm_blend.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index 37ac168fcb60..121481f6aa71 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. Two planes with the
+ * same Z position value have undefined ordering. Note that the Z position
+ * value can also be immutable, to inform userspace about the hard-coded
+ * stacking of planes, see drm_plane_create_zpos_immutable_property().
*
* pixel blend mode:
* Pixel blend mode is set up with drm_plane_create_blend_mode_property().