Re: [PATCH] USB: serial: xr: Add TIOCGRS485 and TIOCSRS485 ioctls

Greg Kroah-Hartman
2023-03-13T15:50:14Z

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