Re: [PATCH net-next 1/4] net: ptp: introduce enum ptp_msg_type

[Richard Cochran]

On Tue, Nov 17, 2020 at 08:31:21PM +0100, Christian Eggers wrote:
> Using a PTP wide enum will obsolete different driver internal defines
> and uses of magic numbers.

I like the general idea, but ...

> +enum ptp_msg_type {
> +     PTP_MSGTYPE_SYNC        = 0x0,
> +     PTP_MSGTYPE_DELAY_REQ   = 0x1,
> +     PTP_MSGTYPE_PDELAY_REQ  = 0x2,
> +     PTP_MSGTYPE_PDELAY_RESP = 0x3,
> +};

I would argue that these should be #defines.  After all, they are
protocol data fields and not an abstract enumerated types.

For example ...

> @@ -103,10 +110,10 @@ struct ptp_header *ptp_parse_header(struct sk_buff 
> *skb, unsigned int type);
>   *
>   * Return: The message type
>   */
> -static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
> +static inline enum ptp_msg_type ptp_get_msgtype(const struct ptp_header *hdr,
>                                unsigned int type)
>  {
> -     u8 msgtype;
> +     enum ptp_msg_type msgtype;
>  
>       if (unlikely(type & PTP_CLASS_V1)) {
>               /* msg type is located at the control field for ptp v1 */

                msgtype = hdr->control;
        } else {
                msgtype = hdr->tsmt & 0x0f;

This assigns directly from protocol data into an enumerated type.

        }

        return msgtype;

Thanks,
Richard