On Mon, Dec 28, 2015 at 02:39:44PM +0000, One Thousand Gnomes wrote: > > https://lkml.kernel.org/r/201102171210.03474.frode@xxxxxxxxxxx > > > > However, the TIOCSRS485-ioctl might not even be the right interface for > > changing transceiver modes, and instead a sysfs-based > > usb-serial-specific interface could be more appropriate for example. > > sysfs works out very badly if modes can be configured routinely at > runtime. In particular the sysfs interface is completely disconnected > from the vhangup() and security model of the tty interface. > > If its the kind if thing just administratively configured at boot then > it's a great interface, just be careful about who has access to it. I think this is something that you only want to configure once (e.g. at boot) and before even opening the tty device as this can change the functions of the pins (e.g. DCD becoming TxD-). If a generic usb-serial-specific interface for this makes sense, I think we should simply prevent mode changes while the port is in use. Johan -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html