SEND_IDLE
if (ssi->send_state == SEND_IDLE) {
if (ssi->send_state == SEND_IDLE)
case SEND_IDLE:
if (ssi->send_state == SEND_IDLE) {
ssip_set_txstate(ssi, SEND_IDLE);
if (ssi->send_state != SEND_IDLE)
case SEND_IDLE:
ssip_set_txstate(ssi, SEND_IDLE);