drm/syncobj: some kerneldoc polish

Complete a few missing bits, fix up the existing xcross-references and
add a bunch more.

v2: Fix typos (Alex).

Cc: Dave Airlie <airlied@gmail.com> via lists.freedesktop.org
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171214203054.20141-4-daniel.vetter@ffwll.ch

1 files changed, 41 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 9b733c510cbf..131695915acd 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -29,9 +29,9 @@
 /**
  * DOC: Overview
  *
- * DRM synchronisation objects (syncobj) are a persistent objects,
- * that contain an optional fence. The fence can be updated with a new
- * fence, or be NULL.
+ * DRM synchronisation objects (syncobj, see struct &drm_syncobj) are
+ * persistent objects that contain an optional fence. The fence can be updated
+ * with a new fence, or be NULL.
  *
  * syncobj's can be waited upon, where it will wait for the underlying
  * fence.
@@ -61,7 +61,8 @@
  * @file_private: drm file private pointer
  * @handle: sync object handle to lookup.
  *
- * Returns a reference to the syncobj pointed to by handle or NULL.
+ * Returns a reference to the syncobj pointed to by handle or NULL. The
+ * reference must be released by calling drm_syncobj_put().
  */
 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
 				     u32 handle)
@@ -229,6 +230,19 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
 	return 0;
 }
 
+/**
+ * drm_syncobj_find_fence - lookup and reference the fence in a sync object
+ * @file_private: drm file private pointer
+ * @handle: sync object handle to lookup.
+ * @fence: out parameter for the fence
+ *
+ * This is just a convenience function that combines drm_syncobj_find() and
+ * drm_syncobj_fence_get().
+ *
+ * Returns 0 on success or a negative error value on failure. On success @fence
+ * contains a reference to the fence, which must be released by calling
+ * dma_fence_put().
+ */
 int drm_syncobj_find_fence(struct drm_file *file_private,
 			   u32 handle,
 			   struct dma_fence **fence)
@@ -269,6 +283,12 @@ EXPORT_SYMBOL(drm_syncobj_free);
  * @out_syncobj: returned syncobj
  * @flags: DRM_SYNCOBJ_* flags
  * @fence: if non-NULL, the syncobj will represent this fence
+ *
+ * This is the first function to create a sync object. After creating, drivers
+ * probably want to make it available to userspace, either through
+ * drm_syncobj_get_handle() or drm_syncobj_get_fd().
+ *
+ * Returns 0 on success or a negative error value on failure.
  */
 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 		       struct dma_fence *fence)
@@ -302,6 +322,14 @@ EXPORT_SYMBOL(drm_syncobj_create);
 
 /**
  * drm_syncobj_get_handle - get a handle from a syncobj
+ * @file_private: drm file private pointer
+ * @syncobj: Sync object to export
+ * @handle: out parameter with the new handle
+ *
+ * Exports a sync object created with drm_syncobj_create() as a handle on
+ * @file_private to userspace.
+ *
+ * Returns 0 on success or a negative error value on failure.
  */
 int drm_syncobj_get_handle(struct drm_file *file_private,
 			   struct drm_syncobj *syncobj, u32 *handle)
@@ -388,6 +416,15 @@ static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj)
 	return 0;
 }
 
+/**
+ * drm_syncobj_get_fd - get a file descriptor from a syncobj
+ * @syncobj: Sync object to export
+ * @p_fd: out parameter with the new file descriptor
+ *
+ * Exports a sync object created with drm_syncobj_create() as a file descriptor.
+ *
+ * Returns 0 on success or a negative error value on failure.
+ */
 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
 {
 	int ret;