diff options
| -rw-r--r-- | drivers/gpu/drm/drm_blend.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 2e5e089dd912..4c62dff14893 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -214,9 +214,11 @@ EXPORT_SYMBOL(drm_rotation_simplify); * This function initializes generic mutable zpos property and enables support * for it in drm core. Drivers can then attach this property to planes to enable * support for configurable planes arrangement during blending operation. - * Once mutable zpos property has been enabled, the DRM core will automatically - * calculate &drm_plane_state.normalized_zpos values. Usually min should be set - * to 0 and max to maximal number of planes for given crtc - 1. + * Drivers that attach a mutable zpos property to any plane should call the + * drm_atomic_normalize_zpos() helper during their implementation of + * &drm_mode_config_funcs.atomic_check(), which will update the normalized zpos + * values and store them in &drm_plane_state.normalized_zpos. Usually min + * should be set to 0 and max to maximal number of planes for given crtc - 1. * * If zpos of some planes cannot be changed (like fixed background or * cursor/topmost planes), driver should adjust min/max values and assign those |