Subject: Re: [PATCH RESEND net-next v7] wwan: core: Support slicing in port TX flow of WWAN subsystem

From: Jakub Kicinski <[email-masked]>
Date: Mon, 13 Mar 2023 16:08:37 -0700

On Wed, 8 Mar 2023 16:19:35 +0800 [email-masked] wrote:
>  /**
>   * wwan_create_port - Add a new WWAN port
>   * @parent: Device to use as parent and shared by all WWAN ports
>   * @type: WWAN port type
>   * @ops: WWAN port operations
> + * @frag_len: WWAN port TX fragments length, if WWAN_NO_FRAGMENT is set,
> + *            the WWAN core don't fragment control packages.
> + * @headroom_len: WWAN port TX fragments reserved headroom length, if WWAN_NO_HEADROOM
> + *                is set, the WWAN core don't reserve headroom in control packages.
>   * @drvdata: Pointer to caller driver data
>   *
>   * Allocate and register a new WWAN port. The port will be automatically exposed
> @@ -86,6 +100,8 @@ struct wwan_port_ops {
>  struct wwan_port *wwan_create_port(struct device *parent,
>  				   enum wwan_port_type type,
>  				   const struct wwan_port_ops *ops,
> +				   size_t frag_len,
> +				   unsigned int headroom_len,
>  				   void *drvdata);
>  

Too many arguments, and poor extensibility.
Please wrap the new params into a capability struct:

struct wwan_port_caps {
	unsigned int frag_len;
	unsigned int headroom_len;
};

pass a pointer to this kind of structure in.

Next time someone needs to add a quirk they can just add a field and
won't need to change all the drivers.