Am Mittwoch, den 11.09.2019, 12:39 +0000 schrieb Joakim Tjernlund: > Every now and then my ttyACM0 hangs up or sends a BREAK char to my device. > I am trying to make ttyACM ignore incoming(over USB) and not emit > any BREAK automatically using termios (IGN_BRK) but that does not make a difference. > > Is BREAK handling unimpl. in ttyACM ? acm_send_break() implements it. But the support is optional in ACM devices. What is bmCapabilities in sysfs for your device? Regards Oliver