Subject: Re: [PATCH net 3/3] ice: Add set_termios tty operations handle to GNSS

From: Jakub Kicinski <[email-masked]>
Date: Wed, 31 Aug 2022 14:54:39 -0700

On Mon, 29 Aug 2022 15:00:49 -0700 Tony Nguyen wrote:
> From: Michal Michalik <[email-masked]>
> 
> Some third party tools (ex. ubxtool) try to change GNSS TTY parameters
> (ex. speed). While being optional implementation, without set_termios
> handle this operation fails and prevents those third party tools from
> working. TTY interface in ice driver is virtual and doesn't need any change
> on set_termios, so is left empty. Add this mock to support all Linux TTY
> APIs.
> 
> Fixes: 43113ff73453 ("ice: add TTY for GNSS module for E810T device")
> Signed-off-by: Michal Michalik <[email-masked]>
> Tested-by: Gurucharan <[email-masked]> (A Contingent worker at Intel)
> Signed-off-by: Tony Nguyen <[email-masked]>

Please CC GNSS and TTY maintainers on the patches relating to 
the TTY/GNSS channel going forward.

CC: Greg, Jiri, Johan

We'll pull in a day or two if there are no objections.

> diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
> index b5a7f246d230..c2dc5e5c8fa4 100644
> --- a/drivers/net/ethernet/intel/ice/ice_gnss.c
> +++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
> @@ -404,11 +404,26 @@ static unsigned int ice_gnss_tty_write_room(struct tty_struct *tty)
>  	return ICE_GNSS_TTY_WRITE_BUF;
>  }
>  
> +/**
> + * ice_gnss_tty_set_termios - mock for set_termios tty operations
> + * @tty: pointer to the tty_struct
> + * @new_termios: pointer to the new termios parameters
> + */
> +static void
> +ice_gnss_tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
> +{
> +	/* Some 3rd party tools (ex. ubxtool) want to change the TTY parameters.
> +	 * In our virtual interface (I2C communication over FW AQ) we don't have
> +	 * to change anything, but we need to implement it to unblock tools.
> +	 */
> +}
> +
>  static const struct tty_operations tty_gps_ops = {
>  	.open =		ice_gnss_tty_open,
>  	.close =	ice_gnss_tty_close,
>  	.write =	ice_gnss_tty_write,
>  	.write_room =	ice_gnss_tty_write_room,
> +	.set_termios =  ice_gnss_tty_set_termios,
>  };
>  
>  /**