From a2511a557eb868dc5fb28808ef58bd8af2e51f3b Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 29 Aug 2016 10:27:53 +0200 Subject: [PATCH] drm/doc: Polish docs for drm_mode_object I figured an overview section here is overkill, and better to just document the 2 structures themselves well enough. v2: Review from Archit: - Appease checkpatch in moved code. - Spelling fixes in the kerneldoc. Reviewed-by: Archit Taneja Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20160829082757.17913-5-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_mode_object.c | 17 ++++++++--- include/drm/drm_mode_object.h | 50 +++++++++++++++++++++++++++++-- 2 files changed, 60 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c index a92aeed51156..6edda8382a4c 100644 --- a/drivers/gpu/drm/drm_mode_object.c +++ b/drivers/gpu/drm/drm_mode_object.c @@ -97,7 +97,7 @@ void drm_mode_object_register(struct drm_device *dev, * for reference counted modeset objects like framebuffers. */ void drm_mode_object_unregister(struct drm_device *dev, - struct drm_mode_object *object) + struct drm_mode_object *object) { mutex_lock(&dev->mode_config.idr_mutex); if (object->id) { @@ -152,7 +152,7 @@ EXPORT_SYMBOL(drm_mode_object_find); * drm_mode_object_unreference - decr the object refcnt * @obj: mode_object * - * This functions decrements the object's refcount if it is a refcounted modeset + * This function decrements the object's refcount if it is a refcounted modeset * object. It is a no-op on any other object. This is used to drop references * acquired with drm_mode_object_reference(). */ @@ -169,7 +169,7 @@ EXPORT_SYMBOL(drm_mode_object_unreference); * drm_mode_object_reference - incr the object refcnt * @obj: mode_object * - * This functions increments the object's refcount if it is a refcounted modeset + * This function increments the object's refcount if it is a refcounted modeset * object. It is a no-op on any other object. References should be dropped again * by calling drm_mode_object_unreference(). */ @@ -218,10 +218,16 @@ EXPORT_SYMBOL(drm_object_attach_property); * @property: property to set * @val: value the property should be set to * - * This functions sets a given property on a given object. This function only + * This function sets a given property on a given object. This function only * changes the software state of the property, it does not call into the * driver's ->set_property callback. * + * Note that atomic drivers should not have any need to call this, the core will + * ensure consistency of values reported back to userspace through the + * appropriate ->atomic_get_property callback. Only legacy drivers should call + * this function to update the tracked value (after clamping and other + * restrictions have been applied). + * * Returns: * Zero on success, error code on failure. */ @@ -252,6 +258,9 @@ EXPORT_SYMBOL(drm_object_property_set_value); * value this might be out of sync with the hardware, depending upon the driver * and property. * + * Atomic drivers should never call this function directly, the core will read + * out property values through the various ->atomic_get_property callbacks. + * * Returns: * Zero on success, error code on failure. */ diff --git a/include/drm/drm_mode_object.h b/include/drm/drm_mode_object.h index b8adb6425f2a..be3d93839ae2 100644 --- a/include/drm/drm_mode_object.h +++ b/include/drm/drm_mode_object.h @@ -27,6 +27,28 @@ struct drm_object_properties; struct drm_property; +/** + * struct drm_mode_object - base structure for modeset objects + * @id: userspace visible identifier + * @type: type of the object, one of DRM_MODE_OBJECT\_\* + * @properties: properties attached to this object, including values + * @refcount: reference count for objects which with dynamic lifetime + * @free_cb: free function callback, only set for objects with dynamic lifetime + * + * Base structure for modeset objects visible to userspace. Objects can be + * looked up using drm_mode_object_find(). Besides basic uapi interface + * properties like @id and @type it provides two services: + * + * - It tracks attached properties and their values. This is used by &drm_crtc, + * &drm_plane and &drm_connector. Properties are attached by calling + * drm_object_attach_property() before the object is visible to userspace. + * + * - For objects with dynamic lifetimes (as indicated by a non-NULL @free_cb) it + * provides reference counting through drm_mode_object_reference() and + * drm_mode_object_unreference(). This is used by &drm_framebuffer, + * &drm_connector and &drm_property_blob. These objects provide specialized + * reference counting wrappers. + */ struct drm_mode_object { uint32_t id; uint32_t type; @@ -36,16 +58,38 @@ struct drm_mode_object { }; #define DRM_OBJECT_MAX_PROPERTY 24 +/** + * struct drm_object_properties - property tracking for &drm_mode_object + */ struct drm_object_properties { + /** + * @count: number of valid properties, must be less than or equal to + * DRM_OBJECT_MAX_PROPERTY. + */ + int count; - /* NOTE: if we ever start dynamically destroying properties (ie. + /** + * @properties: Array of pointers to &drm_property. + * + * NOTE: if we ever start dynamically destroying properties (ie. * not at drm_mode_config_cleanup() time), then we'd have to do * a better job of detaching property from mode objects to avoid * dangling property pointers: */ struct drm_property *properties[DRM_OBJECT_MAX_PROPERTY]; - /* do not read/write values directly, but use drm_object_property_get_value() - * and drm_object_property_set_value(): + + /** + * @values: Array to store the property values, matching @properties. Do + * not read/write values directly, but use + * drm_object_property_get_value() and drm_object_property_set_value(). + * + * Note that atomic drivers do not store mutable properties in this + * array, but only the decoded values in the corresponding state + * structure. The decoding is done using the ->atomic_get_property and + * ->atomic_set_property hooks of the corresponding object. Hence atomic + * drivers should not use drm_object_property_set_value() and + * drm_object_property_get_value() on mutable objects, i.e. those + * without the DRM_MODE_PROP_IMMUTABLE flag set. */ uint64_t values[DRM_OBJECT_MAX_PROPERTY]; }; -- 2.20.1