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

Jarkko Sonninen
2023-03-13T15:56:49Z

On 3/13/23 17:50, Greg Kroah-Hartman wrote:
> 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

For example TCGETS and TCFLSH

- Jarkko