From 05981422ea178c908e451a97ac71dad886c27691 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 22 Apr 2016 22:10:27 +0200 Subject: [PATCH] drm: Improve kerneldoc for new mode object refcounting Slipped through the cracks in my review. The one issue I spotted is that drm_mode_object_find now acquires references and can be used on FB objects, which caused follow-on bugs in get/set_prop ioctls. Follow-up patches will fix that. [airlied: fixup some incr fb/decr object mixups] Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_crtc.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index d078a5c34d48..27c64541876c 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -380,10 +380,9 @@ static struct drm_mode_object *_object_find(struct drm_device *dev, * @id: id of the mode object * @type: type of the mode object * - * Note that framebuffers cannot be looked up with this functions - since those - * are reference counted, they need special treatment. Even with - * DRM_MODE_OBJECT_ANY (although that will simply return NULL - * rather than WARN_ON()). + * This function is used to look up a modeset object. It will acquire a + * reference for reference counted objects. This reference must be dropped again + * by callind drm_mode_object_unreference(). */ struct drm_mode_object *drm_mode_object_find(struct drm_device *dev, uint32_t id, uint32_t type) @@ -398,6 +397,14 @@ struct drm_mode_object *drm_mode_object_find(struct drm_device *dev, } 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 + * object. It is a no-op on any other object. This is used to drop references + * acquired with drm_mode_object_reference(). + */ void drm_mode_object_unreference(struct drm_mode_object *obj) { if (obj->free_cb) { @@ -408,11 +415,12 @@ void drm_mode_object_unreference(struct drm_mode_object *obj) EXPORT_SYMBOL(drm_mode_object_unreference); /** - * drm_mode_object_reference - incr the fb refcnt + * drm_mode_object_reference - incr the object refcnt * @obj: mode_object * - * This function operates only on refcounted objects. - * This functions increments the object's refcount. + * This functions 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(). */ void drm_mode_object_reference(struct drm_mode_object *obj) { -- 2.30.2