drm/ttm: wait for BO idle after the move in ttm_bo_swapout

Final part to avoid pre move waits.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/ttm/ttm_bo.c

@@ -1655,14 +1655,9 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
 	ttm_bo_list_ref_sub(bo, put_count, true);
 
 	/**
-	 * Wait for GPU, then move to system cached.
+	 * Move to system cached
 	 */
 
-	ret = ttm_bo_wait(bo, false, false);
-
-	if (unlikely(ret != 0))
-		goto out;
-
 	if ((bo->mem.placement & swap_placement) != swap_placement) {
 		struct ttm_mem_reg evict_mem;
 
@@ -1677,6 +1672,14 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
 			goto out;
 	}
 
+	/**
+	 * Make sure BO is idle.
+	 */
+
+	ret = ttm_bo_wait(bo, false, false);
+	if (unlikely(ret != 0))
+		goto out;
+
 	ttm_bo_unmap_virtual(bo);
 
 	/**