On Thu, Dec 13, 2018 at 11:13:54AM +0100, Oliver Neukum wrote: > On Do, 2018-12-13 at 10:43 +0100, Johan Hovold wrote: > > On Thu, Dec 13, 2018 at 11:27:56AM +0800, macpaul.lin@xxxxxxxxxxxx wrote: > > > From: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx> > > > > > > + /* handle active handshake triggered by device */ > > > + if (quirks == DISABLE_ECHO) > > > + acm_tty_driver->init_termios.c_lflag &= ~(ECHO); > > > > You cannot change the driver init_termios like this as that will affect > > all cdc-acm devices that are probed later. If this is at all needed, > > this will have to be done at tty install time. > > Right. How do with decide on a sensible default anyway? I think the current defaults are sensible. They are based on tty_std_termios, which has ECHO set, as for most (all?) tty drivers. Johan