drm/nouveau: audit bo->resource usage

Make sure we can at least move and release BOs without backing store.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220707102453.3633-4-christian.koenig@amd.com

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 994879d..35bb0bb 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1008,7 +1008,8 @@ nouveau_bo_move(struct ttm_buffer_object *bo, bool evict,
        }
 
        /* Fake bo copy. */
-       if (old_reg->mem_type == TTM_PL_SYSTEM && !bo->ttm) {
+       if (!old_reg || (old_reg->mem_type == TTM_PL_SYSTEM &&
+                        !bo->ttm)) {
                ttm_bo_move_null(bo, new_reg);
                goto out;
        }