Re: [PATCH net-next v18 06/10] net: phy: phy_port: Store information about a port's upstream

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 27/09/2026 à 15:36, Maxime Chevallier a écrit :
> MII phy_ports are not meant to be connected directly to a link partner.
> They are meant to feed into some media converter devices that will
> expose an MDI phy_port, so far we only support SFP modules for that.
> 
> In the case an MDI phy_port is backed by an MII port (e.g. a SFP
> module's port, backed by the SFP cage port), let's keep track of the
> port id of the MII port backing it.
> 
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Tested-by: Aleksei Sviridkin <f@lex.la>
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
>   drivers/net/phy/phy_device.c | 29 +++++++++++++++++++++++++++--
>   drivers/net/phy/phylink.c    |  5 +++++
>   include/linux/phy.h          |  4 ++++
>   include/linux/phy_port.h     |  3 +++
>   4 files changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ab9631b161bc..2bb4abd0d392 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1403,6 +1403,7 @@ static int phy_sfp_connect_phy(void *upstream, struct phy_device *phy)
>   	int ret;
>   
>   	phydev->has_sfp_mod_phy = true;
> +	phy_set_upstream_port(phy, phydev->sfp_cage_port);
>   
>   	/* If we aren't attached to a netdev, we can't add the SFP PHY to its
>   	 * topology.
> @@ -1436,6 +1437,8 @@ static void phy_sfp_disconnect_phy(void *upstream, struct phy_device *phy)
>   
>   	if (dev)
>   		phy_link_topo_del_phy(dev, phy);
> +
> +	phy_set_upstream_port(phy, NULL);
>   }
>   
>   /**
> @@ -1571,6 +1574,8 @@ static int phy_add_sfp_mod_port(struct phy_device *phydev)
>   	 */
>   	phydev->mod_port = port;
>   
> +	port->upstream_port = phydev->sfp_cage_port;
> +
>   	return 0;
>   }
>   
> @@ -1726,6 +1731,8 @@ static int phy_sfp_probe(struct phy_device *phydev)
>   		}
>   	}
>   
> +	phydev->sfp_cage_port = port;
> +
>   	ret = sfp_bus_add_upstream(bus, phydev, &sfp_phydev_ops);
>   	if (ret)
>   		goto out_port;
> @@ -1735,14 +1742,13 @@ static int phy_sfp_probe(struct phy_device *phydev)
>   	 */
>   	sfp_bus_put(bus);
>   
> -	phydev->sfp_cage_port = port;
> -
>   	return ret;
>   
>   out_port:
>   	if (port) {
>   		phy_del_port(phydev, port);
>   		phy_port_destroy(port);
> +		phydev->sfp_cage_port = NULL;
>   	}
>   out_sfp:
>   	sfp_bus_put(bus);
> @@ -3687,6 +3693,25 @@ struct phy_port *phy_get_sfp_port(struct phy_device *phydev)
>   }
>   EXPORT_SYMBOL_GPL(phy_get_sfp_port);
>   
> +/**
> + * phy_set_upstream_port() - Sets the phy_port controlling the MII this PHY is
> + *			     attached to.
> + * @phydev: pointer to the PHY device we set the upstream of.
> + * @port: The phy_port upstream of this PHY, can be NULL.
> + */
> +void phy_set_upstream_port(struct phy_device *phydev, struct phy_port *port)
> +{
> +	struct phy_port *local_port;
> +
> +	ASSERT_RTNL();
> +
> +	phydev->upstream_port = port;
> +
> +	phy_for_each_port(phydev, local_port)
> +		local_port->upstream_port = port;
> +}
> +EXPORT_SYMBOL_GPL(phy_set_upstream_port);
> +
>   /**
>    * fwnode_mdio_find_device - Given a fwnode, find the mdio_device
>    * @fwnode: pointer to the mdio_device's fwnode
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index db05d2dda429..2583e913cff6 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -4047,6 +4047,8 @@ static int phylink_add_sfp_mod_port(struct phylink *pl)
>   		}
>   	}
>   
> +	port->upstream_port = pl->sfp_cage_port;
> +
>   	pl->mod_port = port;
>   
>   	return 0;
> @@ -4150,6 +4152,8 @@ static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
>   	phy_interface_and(phy->host_interfaces, phylink_sfp_interfaces,
>   			  pl->config->supported_interfaces);
>   
> +	phy_set_upstream_port(phy, pl->sfp_cage_port);
> +
>   	/* Do the initial configuration */
>   	return phylink_sfp_config_phy(pl, phy);
>   }
> @@ -4158,6 +4162,7 @@ static void phylink_sfp_disconnect_phy(void *upstream,
>   				       struct phy_device *phydev)
>   {
>   	phylink_disconnect_phy(upstream);
> +	phy_set_upstream_port(phydev, NULL);
>   }
>   
>   static const struct sfp_upstream_ops sfp_phylink_ops = {
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index dbd6ed5864f2..1fb87d12367b 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -615,6 +615,7 @@ struct phy_oatc14_sqi_capability {
>    * @sfp_bus: SFP bus attached to this PHY's fiber port
>    * @sfp_cage_port: The phy_port connected to the downstream SFP cage
>    * @mod_port: phy_port representing the SFP module, if it is phy-less
> + * @upstream_port: phy_port this PHY's MII attaches to, if any
>    * @attached_dev: The attached enet driver's device instance ptr
>    * @adjust_link: Callback for the enet controller to respond to changes: in the
>    *               link state.
> @@ -809,6 +810,7 @@ struct phy_device {
>   	struct sfp_bus *sfp_bus;
>   	struct phy_port *sfp_cage_port;
>   	struct phy_port *mod_port;
> +	struct phy_port *upstream_port;
>   	struct phylink *phylink;
>   	struct net_device *attached_dev;
>   	struct mii_timestamper *mii_ts;
> @@ -2493,6 +2495,8 @@ int __phy_hwtstamp_set(struct phy_device *phydev,
>   
>   struct phy_port *phy_get_sfp_port(struct phy_device *phydev);
>   
> +void phy_set_upstream_port(struct phy_device *phydev, struct phy_port *port);
> +
>   /**
>    * phy_module_driver() - Helper macro for registering PHY drivers
>    * @__phy_drivers: array of PHY drivers to register
> diff --git a/include/linux/phy_port.h b/include/linux/phy_port.h
> index 4e2a3fdd2f2e..8f45c031cbc1 100644
> --- a/include/linux/phy_port.h
> +++ b/include/linux/phy_port.h
> @@ -40,6 +40,8 @@ struct phy_port_ops {
>    * @head: Used by the port's parent to list ports
>    * @parent_type: The type of device this port is directly connected to
>    * @phy: If the parent is PHY_PORT_PHYDEV, the PHY controlling that port
> + * @upstream_port: Indicates the MII port that feeds this port, if any,
> + *		   e.g. the SFP cage port for a SFP module port.
>    * @ops: Callback ops implemented by the port controller
>    * @pairs: The number of  pairs this port has, 0 if not applicable
>    * @mediums: Bitmask of the physical mediums this port provides access to
> @@ -59,6 +61,7 @@ struct phy_port {
>   	union {
>   		struct phy_device *phy;
>   	};
> +	struct phy_port *upstream_port;
>   
>   	const struct phy_port_ops *ops;
>