Re: [PATCH net-next v18 03/10] net: phylink: Register a phy_port for MAC-driven SFP cages

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

Le 27/09/2026 à 15:36, Maxime Chevallier a écrit :
> phy_port tracks the interfaces that a netdevice feeds into. SFP cages are
> such ports, but so far we are only tracking the ones that are driven by
> PHYs acting as media-converters.
> 
> Let's populate a phy_port for MAC driven SFP cages, handled by phylink.
> 
> This phy_port represents the SFP cage itself, and not the module that
> may be plugged into it. It's therefore not an MDI interface, so only the
> 'interfaces' field is relevant here.
> 
> The phy_port is only populated for 'NETDEV' phylink instances, as
> otherwise we don't have any topology to attach the port to.
> 
> 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/phylink.c | 57 +++++++++++++++++++++++++++++++++++++++
>   1 file changed, 57 insertions(+)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index a7d086cdc9b2..19090916af75 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -14,6 +14,8 @@
>   #include <linux/of_mdio.h>
>   #include <linux/phy.h>
>   #include <linux/phy_fixed.h>
> +#include <linux/phy_link_topology.h>
> +#include <linux/phy_port.h>
>   #include <linux/phylink.h>
>   #include <linux/rtnetlink.h>
>   #include <linux/spinlock.h>
> @@ -93,6 +95,7 @@ struct phylink {
>   	DECLARE_PHY_INTERFACE_MASK(sfp_interfaces);
>   	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
>   	u8 sfp_port;
> +	struct phy_port *sfp_cage_port;
>   
>   	struct eee_config eee_cfg;
>   
> @@ -1767,6 +1770,50 @@ static void phylink_fixed_poll(struct timer_list *t)
>   
>   static const struct sfp_upstream_ops sfp_phylink_ops;
>   
> +static int phylink_create_sfp_cage_port(struct phylink *pl)
> +{
> +	struct phy_port *port;
> +	int ret = 0;
> +
> +	if (!pl->netdev || !pl->sfp_bus)
> +		return 0;
> +
> +	port = phy_port_alloc();
> +	if (!port)
> +		return -ENOMEM;
> +
> +	port->is_sfp = true;
> +	port->is_mii = true;
> +	port->active = true;
> +
> +	phy_interface_and(port->interfaces, pl->config->supported_interfaces,
> +			  phylink_sfp_interfaces);
> +	phy_port_update_supported(port);
> +
> +	ret = phy_link_topo_add_port(pl->netdev, port);
> +	if (ret)
> +		phy_port_destroy(port);
> +	else
> +		pl->sfp_cage_port = port;
> +
> +	return ret;
> +}
> +
> +static void phylink_destroy_sfp_cage_port(struct phylink *pl)
> +{
> +	if (pl->netdev && pl->sfp_cage_port) {
> +		/* The port may still be accessed under RTNL */
> +		rtnl_lock();
> +		phy_link_topo_del_port(pl->netdev, pl->sfp_cage_port);
> +		rtnl_unlock();
> +	}
> +
> +	if (pl->sfp_cage_port)
> +		phy_port_destroy(pl->sfp_cage_port);
> +
> +	pl->sfp_cage_port = NULL;
> +}
> +
>   static int phylink_register_sfp(struct phylink *pl,
>   				const struct fwnode_handle *fwnode)
>   {
> @@ -1784,9 +1831,18 @@ static int phylink_register_sfp(struct phylink *pl,
>   
>   	pl->sfp_bus = bus;
>   
> +	ret = phylink_create_sfp_cage_port(pl);
> +	if (ret) {
> +		sfp_bus_put(bus);
> +		return ret;
> +	}
> +
>   	ret = sfp_bus_add_upstream(bus, pl, &sfp_phylink_ops);
>   	sfp_bus_put(bus);
>   
> +	if (ret)
> +		phylink_destroy_sfp_cage_port(pl);
> +
>   	return ret;
>   }
>   
> @@ -2069,6 +2125,7 @@ EXPORT_SYMBOL_GPL(phylink_create);
>   void phylink_destroy(struct phylink *pl)
>   {
>   	sfp_bus_del_upstream(pl->sfp_bus);
> +	phylink_destroy_sfp_cage_port(pl);
>   	if (pl->link_gpio)
>   		gpiod_put(pl->link_gpio);
>