Re: [PATCH net-next v3 1/3] net: phy: MII-Lite PHY interface mode

From: Andrew Lunn
Date: Wed Jun 25 2025 - 13:04:44 EST


On Wed, Jun 25, 2025 at 06:34:51PM +0200, Kamil Horák - 2N wrote:
> From: Kamil Horák (2N) <kamilh@xxxxxxxx>
>
> Some Broadcom PHYs are capable to operate in simplified MII mode,
> without TXER, RXER, CRS and COL signals as defined for the MII.
> The MII-Lite mode can be used on most Ethernet controllers with full
> MII interface by just leaving the input signals (RXER, CRS, COL)
> inactive. The absence of COL signal makes half-duplex link modes
> impossible but does not interfere with BroadR-Reach link modes on
> Broadcom PHYs, because they are all full-duplex only.
>
> Add MII-Lite interface mode, especially for Broadcom two-wire PHYs.
> Add MII-Lite activation for bcm5481x PHYs.

Please split this patch into two. Add PHY_INTERFACE_MODE_MIILITE to
the core first. Then add support for it to the broadcom PHY.

Splitting it allows you to make the commit message more detailed.

>
> + case PHY_INTERFACE_MODE_MIILITE:
> + link_caps |= BIT(LINK_CAPA_10FD) | BIT(LINK_CAPA_100FD);
> + break;
> +

You could call this out in the commit message.

> * Describes the interface between the MAC and PHY.
> @@ -150,6 +151,7 @@ typedef enum {
> PHY_INTERFACE_MODE_50GBASER,
> PHY_INTERFACE_MODE_LAUI,
> PHY_INTERFACE_MODE_100GBASEP,
> + PHY_INTERFACE_MODE_MIILITE,
> PHY_INTERFACE_MODE_MAX,
> } phy_interface_t;

This enum is not part of the ABI. So you can insert MIILITE directly
after MII.

Andrew