The docs for enum drm_plane_type mention legacy IOCTLs, however the plane type is not tied to legacy IOCTLs, the drm_cursor.primary and cursor fields are. Add a small paragraph to reference these.
Instead, document expectations for primary and cursor planes for non-legacy userspace. Note that these docs are for driver developers, not userspace developers, so internal kernel APIs are mentionned.
Signed-off-by: Simon Ser contact@emersion.fr Reviewed-by: Daniel Vetter daniel@ffwll.ch Cc: Pekka Paalanen ppaalanen@gmail.com --- include/drm/drm_plane.h | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index 1d82b264e5e4..0312a78ffbf1 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -538,10 +538,14 @@ struct drm_plane_funcs { * * For compatibility with legacy userspace, only overlay planes are made * available to userspace by default. Userspace clients may set the - * DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate that they + * &DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate that they * wish to receive a universal plane list containing all plane types. See also * drm_for_each_legacy_plane(). * + * In addition to setting each plane's type, drivers need to setup the + * &drm_crtc.primary and optionally &drm_crtc.cursor pointers for legacy + * IOCTLs. See drm_crtc_init_with_planes(). + * * WARNING: The values of this enum is UABI since they're exposed in the "type" * property. */ @@ -557,19 +561,20 @@ enum drm_plane_type { /** * @DRM_PLANE_TYPE_PRIMARY: * - * Primary planes represent a "main" plane for a CRTC. Primary planes - * are the planes operated upon by CRTC modesetting and flipping - * operations described in the &drm_crtc_funcs.page_flip and - * &drm_crtc_funcs.set_config hooks. + * A primary plane attached to a CRTC is the most likely to be able to + * light up the CRTC when no scaling/cropping is used and the plane + * covers the whole CRTC. */ DRM_PLANE_TYPE_PRIMARY,
/** * @DRM_PLANE_TYPE_CURSOR: * - * Cursor planes represent a "cursor" plane for a CRTC. Cursor planes - * are the planes operated upon by the DRM_IOCTL_MODE_CURSOR and - * DRM_IOCTL_MODE_CURSOR2 IOCTLs. + * A cursor plane attached to a CRTC is more likely to be able to be + * enabled when no scaling/cropping is used and the framebuffer has the + * size indicated by &drm_mode_config.cursor_width and + * &drm_mode_config.cursor_height. Additionally, if the driver doesn't + * support modifiers, the framebuffer should have a linear layout. */ DRM_PLANE_TYPE_CURSOR, };