[PATCH] drm/ttm: fix dma_fence refcount imbalance on error path

[Lin Yi]

the ttm_bo_add_move_fence takes a reference to the struct dma_fence, but
failed to release it on the error path, leading to a memory leak.
add dma_fence_put before return when error occur.

Signed-off-by: Lin Yi <teroincn at 163.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 988416f..41d07fa 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -876,8 +876,10 @@ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
 		reservation_object_add_shared_fence(bo->resv, fence);
 
 		ret = reservation_object_reserve_shared(bo->resv, 1);
-		if (unlikely(ret))
+		if (unlikely(ret)) {
+			dma_fence_put(fence);
 			return ret;
+		}
 
 		dma_fence_put(bo->moving);
 		bo->moving = fence;
-- 
1.9.1