Re: [PATCH RFC net-next 14/19] net: mvpp2: add ethtool flow control configuration support

From: Andrew Lunn
Date: Sun Jan 10 2021 - 12:34:37 EST


> @@ -5373,6 +5402,30 @@ static int mvpp2_ethtool_set_pause_param(struct net_device *dev,
> struct ethtool_pauseparam *pause)
> {
> struct mvpp2_port *port = netdev_priv(dev);
> + int i;
> +
> + if (pause->tx_pause && port->priv->global_tx_fc) {
> + port->tx_fc = true;
> + mvpp2_rxq_enable_fc(port);
> + if (port->priv->percpu_pools) {
> + for (i = 0; i < port->nrxqs; i++)
> + mvpp2_bm_pool_update_fc(port, &port->priv->bm_pools[i], true);
> + } else {
> + mvpp2_bm_pool_update_fc(port, port->pool_long, true);
> + mvpp2_bm_pool_update_fc(port, port->pool_short, true);
> + }
> +
> + } else if (port->priv->global_tx_fc) {
> + port->tx_fc = false;
> + mvpp2_rxq_disable_fc(port);
> + if (port->priv->percpu_pools) {
> + for (i = 0; i < port->nrxqs; i++)
> + mvpp2_bm_pool_update_fc(port, &port->priv->bm_pools[i], false);
> + } else {
> + mvpp2_bm_pool_update_fc(port, port->pool_long, false);
> + mvpp2_bm_pool_update_fc(port, port->pool_short, false);
> + }
> + }


This looks wrong. Flow control is normally the result of auto
negotiation. Both ends need to agree to it. Which is why
mvpp2_ethtool_set_pause_param() passes the users request onto phylink.
phylink will handle the autoneg and then ask the MAC to setup flow
control depending on the result in mvpp2_mac_link_up().

Andrew