drm/nouveau/ttm: explicitly wait for bo idle before memcpy buffer move

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1180,13 +1180,8 @@ nouveau_bo_move(struct ttm_buffer_object *bo, bool evict, bool intr,
 		goto out;
 	}
 
-	/* CPU copy if we have no accelerated method available */
-	if (!drm->ttm.move) {
-		ret = ttm_bo_move_memcpy(bo, evict, no_wait_gpu, new_mem);
-		goto out;
-	}
-
 	/* Hardware assisted copy. */
+	if (drm->ttm.move) {
 		if (new_mem->mem_type == TTM_PL_SYSTEM)
 			ret = nouveau_bo_move_flipd(bo, evict, intr,
 						    no_wait_gpu, new_mem);
@@ -1196,11 +1191,15 @@ nouveau_bo_move(struct ttm_buffer_object *bo, bool evict, bool intr,
 		else
 			ret = nouveau_bo_move_m2mf(bo, evict, intr,
 						   no_wait_gpu, new_mem);
-
 		if (!ret)
 			goto out;
+	}
 
 	/* Fallback to software copy. */
+	spin_lock(&bo->bdev->fence_lock);
+	ret = ttm_bo_wait(bo, true, intr, no_wait_gpu);
+	spin_unlock(&bo->bdev->fence_lock);
+	if (ret == 0)
 		ret = ttm_bo_move_memcpy(bo, evict, no_wait_gpu, new_mem);
 
 out: