Subject: Re: [PATCH v1 RFC 7/7] Modify tag_ksz.c so that tail tag code can be used by other KSZ switch drivers

From: Pavel Machek <[email-masked]>
Date: Wed, 11 Oct 2017 22:45:28 +0200

Hi!

> +#define	KSZ_INGRESS_TAG_LEN		1

This define is now (or should be) unused, so you can delete it, no?

> _#define	KSZ_EGRESS_TAG_LEN	1

And I'd delete this define, too. Having constant for something that's
variable is quite confusing :-).

Plus you are really doing too much inside single patch.

> + * For Egress (KSZ9477 -> Host), 1 byte is added before FCS.
> + * ---------------------------------------------------------------------------
> + * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
> + * ---------------------------------------------------------------------------
> + * tag0 : zero-based value represents port
> + *	  (eg, 0x00=port1, 0x02=port3, 0x06=port7)
> + */
> +
> +#define KSZ9477_INGRESS_TAG_LEN		2
> +#define KSZ9477_PTP_TAG_LEN		4
> +#define KSZ9477_PTP_TAG_INDICATION	0x80
> +
> +#define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
> +#define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
> +
> +static int ksz9477_get_tag(u8 *tag, int *port)
> +{
> +	int len = KSZ_EGRESS_TAG_LEN;
> +
> +	/* Extra 4-bytes PTP timestamp */
> +	if (tag[0] & KSZ9477_PTP_TAG_INDICATION)
> +		len += KSZ9477_PTP_TAG_LEN;
> +	*port = tag[0] & 7;
> +	return len;
> +}
> +
> +static void ksz9477_set_tag(void *ptr, u8 *addr, int p)
> +{
> +	u16 *tag = (u16 *)ptr;
> +
> +	*tag = 1 << p;
> +	if (!memcmp(addr, special_mult_addr, ETH_ALEN))
> +		*tag |= KSZ9477_TAIL_TAG_OVERRIDE;
> +	*tag = cpu_to_be16(*tag);
> +}

These are new features that were not there before, right?
								Pavel
								
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