diff --git a/block/blk-core.c b/block/blk-core.c
index 94bf37f..ce08f0a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -708,7 +708,7 @@ static void __submit_bio(struct bio *bio)
  *
  * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio.
  * bio_list_on_stack[1] contains bios that were submitted before the current
- *	->submit_bio_bio, but that haven't been processed yet.
+ *	->submit_bio, but that haven't been processed yet.
  */
 static void __submit_bio_noacct(struct bio *bio)
 {
@@ -975,7 +975,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	blk_qc_t cookie = READ_ONCE(bio->bi_cookie);
-	int ret;
+	int ret = 0;
 
 	if (cookie == BLK_QC_T_NONE ||
 	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
@@ -985,10 +985,14 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 
 	if (blk_queue_enter(q, BLK_MQ_REQ_NOWAIT))
 		return 0;
-	if (WARN_ON_ONCE(!queue_is_mq(q)))
-		ret = 0;	/* not yet implemented, should not happen */
-	else
+	if (queue_is_mq(q)) {
 		ret = blk_mq_poll(q, cookie, iob, flags);
+	} else {
+		struct gendisk *disk = q->disk;
+
+		if (disk && disk->fops->poll_bio)
+			ret = disk->fops->poll_bio(bio, iob, flags);
+	}
 	blk_queue_exit(q);
 	return ret;
 }