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Diffstat (limited to 'drivers/gpu/drm/drm_blend.c')
| -rw-r--r-- | drivers/gpu/drm/drm_blend.c | 7 |
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(). |