LQM_ECHO
cx->physical->hdlc.lqm.method &= ~LQM_ECHO;
if (cx->physical->hdlc.lqm.method & LQM_ECHO &&
cx->physical->hdlc.lqm.method |= LQM_ECHO;
} else if (p->hdlc.lqm.method & LQM_ECHO) {
physical->hdlc.lqm.method = lcp->cfg.echo ? LQM_ECHO : 0;
if (lcp->want_lqrperiod || physical->hdlc.lqm.method & LQM_ECHO) {
if (method == LQM_ECHO)