EPP_PTTBIT
hi.data.cs.ptt = !!(bc->stat & EPP_PTTBIT);
hi.data.ocs.ptt = !!(bc->stat & EPP_PTTBIT);
#define EPP_NTEF EPP_PTTBIT
if (bc->hdlctx.state == tx_tail && !(stat & EPP_PTTBIT))
#define EPP_NTEF EPP_PTTBIT