> gpsd uses TIOCMIWAIT to get a wakeup from a PPS signal connected to a modem > control line. That path might have the same problem and/or some ideas on how > to handle the data case. TIOCMIWAIT should be fine. The data processing is deferred but very few devices defer processing of modem change events. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html