1 files changed, 19 insertions, 11 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 7cc904d3a4d1..4834c463c38b 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -343,19 +343,25 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
         if (ret)
                 goto out;
 
+        /*
+         * Single TTM move. NOP.
+         */
         if (old_iomap == NULL && new_iomap == NULL)
                 goto out2;
+
+        /*
+         * Move nonexistent data. NOP.
+         */
         if (old_iomap == NULL && ttm == NULL)
                 goto out2;
 
-        if (ttm->state == tt_unpopulated) {
+        /*
+         * TTM might be null for moves within the same region.
+         */
+        if (ttm && ttm->state == tt_unpopulated) {
                 ret = ttm->bdev->driver->ttm_tt_populate(ttm);
-                if (ret) {
-                        /* if we fail here don't nuke the mm node
-                         * as the bo still owns it */
-                        old_copy.mm_node = NULL;
+                if (ret)
                         goto out1;
-                }
         }
 
         add = 0;
@@ -381,11 +387,8 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
                                                    prot);
                 } else
                         ret = ttm_copy_io_page(new_iomap, old_iomap, page);
-                if (ret) {
-                        /* failing here, means keep old copy as-is */
-                        old_copy.mm_node = NULL;
+                if (ret)
                         goto out1;
-                }
         }
         mb();
 out2:
@@ -403,7 +406,12 @@ out1:
         ttm_mem_reg_iounmap(bdev, old_mem, new_iomap);
 out:
         ttm_mem_reg_iounmap(bdev, &old_copy, old_iomap);
-        ttm_bo_mem_put(bo, &old_copy);
+
+        /*
+         * On error, keep the mm node!
+         */
+        if (!ret)
+                ttm_bo_mem_put(bo, &old_copy);
         return ret;
 }
 EXPORT_SYMBOL(ttm_bo_move_memcpy);