diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index d948cd522431..6ed05ca65a0f 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1744,9 +1744,11 @@ static blk_qc_t dm_process_bio(struct mapped_device *md,
 	}
 
 	/*
-	 * If in ->queue_bio we need to use blk_queue_split(), otherwise
+	 * If in ->submit_bio we need to use blk_queue_split(), otherwise
 	 * queue_limits for abnormal requests (e.g. discard, writesame, etc)
 	 * won't be imposed.
+	 * If called from dm_wq_work() for deferred bio processing, bio
+	 * was already handled by following code with previous ->submit_bio.
 	 */
 	if (current->bio_list) {
 		if (is_abnormal_io(bio))