[PATCH 5/6] drm/doc: diagram for mode objects and properties

From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: linux-doc@vger.kernel.org
Cc: DRI Development <dri-devel@lists.freedesktop.org>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Manasi Navare <manasi.d.navare@intel.com>
Subject: [PATCH 5/6] drm/doc: diagram for mode objects and properties
Date: Tue, 28 Feb 2017 18:13:18 +0100	[thread overview]
Message-ID: <20170228171319.1786-6-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20170228171319.1786-1-daniel.vetter@ffwll.ch>

Resulted in confusion a few times in the past.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 Documentation/gpu/drm-kms.rst | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 17a4cd5b14fd..20378881445f 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -161,6 +161,28 @@ KMS Core Structures and Functions
 Modeset Base Object Abstraction
 ===============================
 
+.. kernel-render:: DOT
+   :alt: Mode Objects and Properties
+   :caption: Mode Objects and Properties
+
+   digraph {
+      node [shape=box]
+
+      "drm_property A" -> "drm_mode_object A"
+      "drm_property A" -> "drm_mode_object B"
+      "drm_property B" -> "drm_mode_object A"
+   }
+
+The base structure for all KMS objects is :c:type:`struct drm_mode_object
+<drm_mode_object>`. One of the base services is provides is tracking properties,
+which are especially important for the atomic IOCTL (see `Atomic Mode
+Setting`_). The somewhat surprising part here is that properties are not
+directly instantiated on each object, but free-standing mode objects themselves,
+represented by :c:type:`struct drm_property <drm_property>`, which only specify
+the type and value range of a property. Any given property can be attached
+multiple times to different objects using :c:func:`drm_object_attach_property()
+<drm_object_attach_property>`.
+
 .. kernel-doc:: include/drm/drm_mode_object.h
    :internal:
 
-- 
2.11.0

