static struct acm *acm_get_by_minor(unsigned int minor)
{
	struct acm *acm;

	mutex_lock(&acm_minors_lock);
	acm = idr_find(&acm_minors, minor);
	if (acm) {
		mutex_lock(&acm->mutex);
		if (acm->disconnected) {
			mutex_unlock(&acm->mutex);
			acm = NULL;
		} else {
			tty_port_get(&acm->port);
			mutex_unlock(&acm->mutex);
		}
	}
	mutex_unlock(&acm_minors_lock);
	return acm;
}

Unknown