Am Dienstag, den 27.06.2017, 19:43 +1000 schrieb Stuart Longland: > Maybe a good start would be a "standard" option (referring to the > physical signalling standard, TTL/RS-232/RS-422/RS-485), that lists the > available standards when read and shows the "selected" standard in > brackets (like the 'trigger' option of the LEDs sysfs interface)… so for > this case: > > # cat /sys/class/tty/ttyUSB0/standard > [rs232] rs422 rs485 rs485fd > > and to select 4-wire ("full duplex") RS-485, one does: > # echo rs485fd > /sys/class/tty/ttyUSB0/standard This looks like something that people will put into udev. So the switch will be done via udev, but the user not necessarily started via udev. Looks like a race to me. And what do you if the interface is already opened and the sysfs interface is used? Regards Oliver -- 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