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authorThierry Reding <treding@nvidia.com>2017-11-20 16:09:59 +0100
committerThierry Reding <treding@nvidia.com>2017-12-14 14:20:35 +0100
commitca40cfc85e548424e39dc3aebe61873535ddf7b6 (patch)
tree4a2f09712171ff64997d0357a99402d11c5ce54c /drivers/gpu/drm/drm_blend.c
parent170178fe99dd212bf25e70c89bc4b6e195564ffc (diff)
drm/atomic-helper: Make zpos property kerneldoc less misleading
kerneldoc for drm_plane_create_zpos_property() says that the DRM core will automatically calculate the normalized zpos values, but it doesn't actually do that anymore since commit 38d868e41c4b ("drm: Don't force all planes to be added to the state due to zpos"). Instead, drivers are supposed to explicitly call the drm_atomic_normalize_zpos() function. Change the kerneldoc comment to reflect that. v2: reference the commit that introduced the kerneldoc unclarity Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171120150959.26913-1-thierry.reding@gmail.com
Diffstat (limited to 'drivers/gpu/drm/drm_blend.c')
-rw-r--r--drivers/gpu/drm/drm_blend.c8
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