1 files changed, 4 insertions, 1 deletions

diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index d81b0ba9921f..f262da180117 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -459,10 +459,13 @@ __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
  * but using the internal interval tree to accelerate the search for the
  * starting node, and so not safe against removal of elements. It assumes
  * that @end is within (or is the upper limit of) the drm_mm allocator.
+ * If [@start, @end] are beyond the range of the drm_mm, the iterator may walk
+ * over the special _unallocated_ &drm_mm.head_node, and may even continue
+ * indefinitely.
  */
 #define drm_mm_for_each_node_in_range(node__, mm__, start__, end__)     \
         for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
-             node__ && node__->start < (end__);                         \
+             node__->start < (end__);                                   \
              node__ = list_next_entry(node__, node_list))
 
 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,