Re: [PATCH net-next 5/6] net: dsa: use swnode fixed-link if using default params

Andy Shevchenko
2022-07-15T20:11:51Z

On Fri, Jul 15, 2022 at 05:01:48PM +0100, Russell King (Oracle) wrote:
> Create and use a swnode fixed-link specification for phylink if no
> parameters are given in DT for a fixed-link. This allows phylink to
> be used for "default" cases for DSA and CPU ports. Enable the use
> of phylink in all cases for DSA and CPU ports.

> Co-developed by Vladimir Oltean and myself.

Why not to use

Co-developed-by: Vladimir Oltean <vladimir.oltean@nxp.com>

?

> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Reviewed-by: Marek Behún <kabel@kernel.org>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

...

> +static struct {
> + unsigned long mask;
> + int speed;
> + int duplex;
> +} phylink_caps_params[] = {
> + { MAC_400000FD, SPEED_400000, DUPLEX_FULL },
> + { MAC_200000FD, SPEED_200000, DUPLEX_FULL },
> + { MAC_100000FD, SPEED_100000, DUPLEX_FULL },
> + { MAC_56000FD, SPEED_56000, DUPLEX_FULL },
> + { MAC_50000FD, SPEED_50000, DUPLEX_FULL },
> + { MAC_40000FD, SPEED_40000, DUPLEX_FULL },
> + { MAC_25000FD, SPEED_25000, DUPLEX_FULL },
> + { MAC_20000FD, SPEED_20000, DUPLEX_FULL },
> + { MAC_10000FD, SPEED_10000, DUPLEX_FULL },
> + { MAC_5000FD, SPEED_5000, DUPLEX_FULL },
> + { MAC_2500FD, SPEED_2500, DUPLEX_FULL },
> + { MAC_1000FD, SPEED_1000, DUPLEX_FULL },
> + { MAC_100FD, SPEED_100, DUPLEX_FULL },
> + { MAC_10FD, SPEED_10, DUPLEX_FULL },
> + { MAC_1000HD, SPEED_1000, DUPLEX_HALF },
> + { MAC_100HD, SPEED_100, DUPLEX_HALF },
> + { MAC_10HD, SPEED_10, DUPLEX_HALF },
> +};
> +
> +static int dsa_port_find_max_speed(unsigned long caps, int *speed, int *duplex)
> +{
> + int i;
> +
> + *speed = SPEED_UNKNOWN;
> + *duplex = DUPLEX_UNKNOWN;
> +
> + for (i = 0; i < ARRAY_SIZE(phylink_caps_params); i++) {
> + if (caps & phylink_caps_params[i].mask) {
> + *speed = phylink_caps_params[i].speed;
> + *duplex = phylink_caps_params[i].duplex;

> + break;

With the below check it's way too protective programming.

return 0;

> + }
> + }
> +
> + return *speed == SPEED_UNKNOWN ? -EINVAL : 0;

return -EINVAL;

> +}

...

> +static struct fwnode_handle *dsa_port_get_fwnode(struct dsa_port *dp,
> + phy_interface_t mode)
> +{

> + struct property_entry fixed_link_props[3] = { };
> + struct property_entry port_props[3] = {};

A bit of consistency in the assignments?

Also it seems you are using up to 2 for the first one and only 1 in the second
one. IIUC it requires a terminator entry, so it means 3 and 2. Do we really
need 3 in the second case?

> + struct fwnode_handle *fixed_link_fwnode;
> + struct fwnode_handle *new_port_fwnode;
> + struct device_node *dn = dp->dn;
> + struct device_node *phy_node;
> + int err, speed, duplex;
> + unsigned long caps;
> +
> + phy_node = of_parse_phandle(dn, "phy-handle", 0);

fwnode in the name, why not to use fwnode APIs?

fwnode_find_reference();

> + of_node_put(phy_node);
> + if (phy_node || of_phy_is_fixed_link(dn))
> + /* Nothing broken, nothing to fix.
> + * TODO: As discussed with Russell, maybe phylink could provide
> + * a more comprehensive helper to determine what constitutes a
> + * valid fwnode binding than this guerilla kludge.
> + */
> + return of_fwnode_handle(dn);
> +
> + if (mode == PHY_INTERFACE_MODE_NA)
> + dsa_port_find_max_caps(dp, &mode, &caps);
> + else
> + caps = dp->pl_config.mac_capabilities &
> + phylink_interface_to_caps(mode);
> +
> + err = dsa_port_find_max_speed(caps, &speed, &duplex);
> + if (err)
> + return ERR_PTR(err);
> +
> + fixed_link_props[0] = PROPERTY_ENTRY_U32("speed", speed);
> + if (duplex == DUPLEX_FULL)
> + fixed_link_props[1] = PROPERTY_ENTRY_BOOL("full-duplex");
> +
> + port_props[0] = PROPERTY_ENTRY_STRING("phy-mode", phy_modes(mode));
> +
> + new_port_fwnode = fwnode_create_software_node(port_props, NULL);
> + if (IS_ERR(new_port_fwnode))
> + return new_port_fwnode;
> +
> + /* Node needs to be named so that phylink's call to
> + * fwnode_get_named_child_node() finds it.
> + */
> + fixed_link_fwnode = fwnode_create_named_software_node(fixed_link_props,
> + new_port_fwnode,
> + "fixed-link");
> + if (IS_ERR(fixed_link_fwnode)) {
> + fwnode_remove_software_node(new_port_fwnode);
> + return fixed_link_fwnode;
> + }
> +
> + return new_port_fwnode;
> +}

--
With Best Regards,
Andy Shevchenko