On Mon, Mar 13, 2023 at 05:07:59PM +0200, Jarkko Sonninen wrote: > On 3/13/23 09:53, Greg Kroah-Hartman wrote: > > On Mon, Mar 13, 2023 at 09:49:26AM +0200, Jarkko Sonninen wrote: > > > > > +{ > > > > > + void __user *argp = (void __user *)arg; > > > > > + > > > > > + switch (cmd) { > > > > > + case TIOCGRS485: > > > > > + return xr_get_rs485_config(tty, argp); > > > > > + case TIOCSRS485: > > > > > + return xr_set_rs485_config(tty, argp); > > > > > + } > > > > > + return -ENOIOCTLCMD; > > > > Wrong ioctl return value :( > > > What is the correct ioctl error return value ? > > > ENOIOCTLCMD was used in most places in usb serial as an error return. > > ENOTTY is the correct one for when an ioctl is not handled by the ioctl > > call. > > > > thanks, > > > > greg k-h > > Using ENOTTY breaks all other tty ioctls. What other tty ioctls? confused, greg k-h