diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
index f5396f26ddb48c38a2d74e8f070be912e8ff461f..f9ec38281ff208022ea24b1c8dd2055be3704b0a 100644
--- a/drivers/mtd/devices/powernv_flash.c
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -78,7 +78,9 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 		rc = opal_flash_erase(info->id, offset, len, token);
 		break;
 	default:
-		BUG_ON(1);
+		WARN_ON_ONCE(1);
+		opal_async_release_token(token);
+		return -EIO;
 	}
 
 	if (rc != OPAL_ASYNC_COMPLETION) {