Commit 7e5d1e12 authored by Simon Ser's avatar Simon Ser
Browse files

drm/doc: fix drm_plane_type docs 



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: default avatarSimon Ser <contact@emersion.fr>
Reviewed-by: default avatarDaniel Vetter <daniel@ffwll.ch>
Acked-by: default avatarPekka Paalanen <pekka.paalanen@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115110626.12233-1-contact@emersion.fr
parent 25e524bf

include/drm/drm_plane.h

+13 −8
Original line number Diff line number Diff line
@@ -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,

};