Re: [PATCH net-next v1 5/5] net: dsa: microchip: add support for side MDIO interface in LAN937x

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Mon, Oct 28, 2024 at 01:15:42PM +0100, Andrew Lunn wrote:
> > +static const u8 lan9370_phy_addr[] = {
> > +	[0] = 2, /* Port 1, T1 AFE0 */
> > +	[1] = 3, /* Port 2, T1 AFE1 */
> > +	[2] = 5, /* Port 3, T1 AFE3 */
> > +	[3] = 6, /* Port 4, T1 AFE4 */
> > +	[4] = U8_MAX, /* Port 5, RGMII 2 */
> > +};
> 
> I think it would be good to add a #define for U8_MAX which gives a
> hint at its meaning.

ack
 
> > +	for (i = 0; i < dev->info->port_cnt; i++) {
> > +		if (phy_addr_map[i] == U8_MAX)
> > +			dev->phy_addr_map[i] = phy_addr_map[i];
> > +		else
> > +			dev->phy_addr_map[i] = phy_addr_map[i] + offset;
> > +	}
> 
> My first guess was that U8_MAX means the PHY is external, so could be
> on any address depending on strapping. Looking at this code, i'm not
> sure it does actually mean that.

Yes, the U8_MAX for ports without integrated PHYs. This code calculates address
for integrated PHYs, which can be different depending on strap
configuration.

I'll use some different define.

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