mtd_unlock
ret = mtd_unlock(mtd, einfo.start, einfo.length);
err = mtd_unlock(subdev, ofs, size);
EXPORT_SYMBOL_GPL(mtd_unlock);
error = mtd_unlock(mtd, 0, mtd->size);
int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);