Re: [PATCH net-next v3 03/10] net: sparx5: add hostmode with phylink support

From: Russell King (Oracle)
Date: Mon Jun 07 2021 - 05:16:00 EST


On Fri, Jun 04, 2021 at 10:55:53AM +0200, Steen Hegelund wrote:
> +static void sparx5_phylink_mac_config(struct phylink_config *config,
> + unsigned int mode,
> + const struct phylink_link_state *state)
> +{
> + struct sparx5_port *port = netdev_priv(to_net_dev(config->dev));
> + struct sparx5_port_config conf;
> +
> + conf = port->conf;
> + conf.power_down = false;
> + conf.portmode = state->interface;
> + conf.speed = state->speed;
> + conf.autoneg = state->an_enabled;
> + conf.pause = state->pause;
> +
> + if (state->interface == PHY_INTERFACE_MODE_10GBASER) {
> + if (state->speed == SPEED_UNKNOWN) {
> + /* When a SFP is plugged in we use capabilities to
> + * default to the highest supported speed
> + */
> + if (phylink_test(state->advertising, 25000baseSR_Full) ||
> + phylink_test(state->advertising, 25000baseCR_Full))
> + conf.speed = SPEED_25000;
> + else if (state->interface == PHY_INTERFACE_MODE_10GBASER)
> + conf.speed = SPEED_10000;
> + } else if (state->speed == SPEED_2500) {
> + conf.portmode = PHY_INTERFACE_MODE_2500BASEX;
> + } else if (state->speed == SPEED_1000) {
> + conf.portmode = PHY_INTERFACE_MODE_1000BASEX;
> + }

1) As detailed in the documentation for phylink, state->speed is not
guaranteed to be valid in the mac_config method.

2) We clearly need PHY_INTERFACE_MODE_25GBASER rather than working
around this by testing bits in the advertising bitmap.

3) I really don't get what's going on with setting the port mode to
2500base-X and 1000base-X here when state->interface is 10GBASER.

> + if (phylink_test(state->advertising, FIBRE))
> + conf.media = PHY_MEDIA_SR;
> + else
> + conf.media = PHY_MEDIA_DAC;
> + }
> +
> + if (!port_conf_has_changed(&port->conf, &conf))
> + return;
> +}
> +
> +static void sparx5_phylink_mac_link_up(struct phylink_config *config,
> + struct phy_device *phy,
> + unsigned int mode,
> + phy_interface_t interface,
> + int speed, int duplex,
> + bool tx_pause, bool rx_pause)
> +{

This is the only place that the MAC is guaranteed to know the
negotiated speed.

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