[PATCH 2/3] drm/ttm: fix the documentation of ttm_bo_init

Nicolai Hähnle nhaehnle at gmail.com
Tue Feb 14 10:37:43 UTC 2017

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

As the comment says: callers of ttm_bo_init cannot rely on having the
only reference to the BO when the function returns successfully.

Signed-off-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
 include/drm/ttm/ttm_bo_api.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index d44b8e4..7b2807f 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -521,7 +521,11 @@ extern int ttm_bo_init_top(struct ttm_bo_device *bdev,
  * As this object may be part of a larger structure, this function,
  * together with the @destroy function,
  * enables driver-specific objects derived from a ttm_buffer_object.
- * On successful return, the object kref and list_kref are set to 1.
+ *
+ * On successful return, the caller owns an object kref to @bo. The kref and
+ * list_kref are usually set to 1, but note that in some situations, other
+ * tasks may already be holding references to @bo as well.
+ *
  * If a failure occurs, the function will call the @destroy function, or
  * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
  * illegal and will likely cause memory corruption.

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