From: Nicolai Hähnle <nicolai.haehnle@xxxxxxx> 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 6e8eaee..5add713 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -520,7 +520,11 @@ 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. -- 2.9.3
