On Wed, 2019-09-11 at 20:27 +0200, Oliver Neukum wrote: > Am Mittwoch, den 11.09.2019, 14:34 +0000 schrieb Joakim Tjernlund: > > On Wed, 2019-09-11 at 16:22 +0200, Oliver Neukum wrote: > > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > > > > > > > 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. > > > > Yes, I se that funktion but I don't see how one can ignore received BREAKs > > If I set IGN_BRK on /dev/ttyACM0 I expect that every BREAK should just be ignored > > Handling breaks looks a bit broken on CDC-ACM. > Could you test the attached patch? > Sure, I can test it but from looking at the patch it seems like ACM already ignores BREAKs(hardcoded) and with your patch you actually start reporting them. My problem is sudden disconnects I cannot explain but I think they are connect to BREAKs I have seen these errors in dmesg though, not sure if they help the diagnose: [181780.167987] usb usb1-port6: disabled by hub (EMI?), re-enabling... [181780.168208] cdc_acm 1-6.3:1.1: acm_ctrl_irq - usb_submit_urb failed: -19 [181780.167996] usb 1-6: USB disconnect, device number 30 [181780.176548] usb 1-6-port2: attempt power cycle [181781.772847] usb 1-6.3: USB disconnect, device number 32 [181781.773134] cdc_acm 1-6.3:1.1: failed to set dtr/rts
