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

From: Jarkko Sonninen
Date: Mon Mar 13 2023 - 11:56:49 EST


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