Date:   Mon, 13 Mar 2023 08:53:43 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Jarkko Sonninen <kasper@iki.fi>
Cc:     Johan Hovold <johan@kernel.org>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: serial: xr: Add TIOCGRS485 and TIOCSRS485 ioctls
Message-ID: <ZA7Wh2Z/DdKOsOYr@kroah.com>
References: <20230313010416.845252-1-kasper@iki.fi>
 <ZA7KIs2jA/acpN9n@kroah.com>
 <a1ba59be-30aa-08e9-65e7-2c458cc164f9@iki.fi>
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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