drm/ttm: remove NULL checks when calling ttm_tt_destroy

The function is a no-op with a NULL pointer.
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

@@ -147,8 +147,7 @@ static void ttm_bo_release_list(struct kref *list_kref)
 	BUG_ON(!list_empty(&bo->lru));
 	BUG_ON(!list_empty(&bo->ddestroy));
 
-	if (bo->ttm)
-		ttm_tt_destroy(bo->ttm);
+	ttm_tt_destroy(bo->ttm);
 	atomic_dec(&bo->glob->bo_count);
 	if (bo->resv == &bo->ttm_resv)
 		reservation_object_fini(&bo->ttm_resv);
@@ -396,7 +395,7 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 
 out_err:
 	new_man = &bdev->man[bo->mem.mem_type];
-	if ((new_man->flags & TTM_MEMTYPE_FLAG_FIXED) && bo->ttm) {
+	if (new_man->flags & TTM_MEMTYPE_FLAG_FIXED) {
 		ttm_tt_destroy(bo->ttm);
 		bo->ttm = NULL;
 	}
@@ -417,10 +416,8 @@ static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
 	if (bo->bdev->driver->move_notify)
 		bo->bdev->driver->move_notify(bo, NULL);
 
-	if (bo->ttm) {
-		ttm_tt_destroy(bo->ttm);
-		bo->ttm = NULL;
-	}
+	ttm_tt_destroy(bo->ttm);
+	bo->ttm = NULL;
 	ttm_bo_mem_put(bo, &bo->mem);
 
 	ww_mutex_unlock (&bo->resv->lock);

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -400,7 +400,7 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	*old_mem = *new_mem;
 	new_mem->mm_node = NULL;
 
-	if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) && (ttm != NULL)) {
+	if (man->flags & TTM_MEMTYPE_FLAG_FIXED) {
 		ttm_tt_destroy(ttm);
 		bo->ttm = NULL;
 	}
@@ -647,8 +647,7 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 		if (ret)
 			return ret;
 
-		if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
-		    (bo->ttm != NULL)) {
+		if (man->flags & TTM_MEMTYPE_FLAG_FIXED) {
 			ttm_tt_destroy(bo->ttm);
 			bo->ttm = NULL;
 		}

drivers/gpu/drm/ttm/ttm_tt.c

@@ -168,7 +168,7 @@ void ttm_tt_destroy(struct ttm_tt *ttm)
 {
 	int ret;
 
-	if (unlikely(ttm == NULL))
+	if (ttm == NULL)
 		return;
 
 	if (ttm->state == tt_bound) {