Re: [RFC PATCH 2/3] net: sparx5: Add Sparx5 switchdev driver

[Steen Hegelund]

On 27.11.2020 18:15, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> This is a very large driver, which is going to make it slow to review.
Hi Andrew,

Yes I am aware of that, but I think that what is available with this
series, makes for a nice package that can be tested by us, and used by
our customers.

> > +static int sparx5_probe_port(struct sparx5 *sparx5,
> > +                          struct device_node *portnp,
> > +                          struct phy *serdes,
> > +                          u32 portno,
> > +                          struct sparx5_port_config *conf)
> > +{
> > +     phy_interface_t phy_mode = conf->phy_mode;
> > +     struct sparx5_port *spx5_port;
> > +     struct net_device *ndev;
> > +     struct phylink *phylink;
> > +     int err;
> > +
> > +     err = sparx5_create_targets(sparx5);
> > +     if (err)
> > +             return err;
> > +     ndev = sparx5_create_netdev(sparx5, portno);
> > +     if (IS_ERR(ndev)) {
> > +             dev_err(sparx5->dev, "Could not create net device: %02u\n", portno);
> > +             return PTR_ERR(ndev);
> > +     }
> > +     spx5_port = netdev_priv(ndev);
> > +     spx5_port->of_node = portnp;
> > +     spx5_port->serdes = serdes;
> > +     spx5_port->pvid = NULL_VID;
> > +     spx5_port->signd_internal = true;
> > +     spx5_port->signd_active_high = true;
> > +     spx5_port->signd_enable = true;
> > +     spx5_port->flow_control = false;
> > +     spx5_port->max_vlan_tags = SPX5_PORT_MAX_TAGS_NONE;
> > +     spx5_port->vlan_type = SPX5_VLAN_PORT_TYPE_UNAWARE;
> > +     spx5_port->custom_etype = 0x8880; /* Vitesse */
> > +     conf->portmode = conf->phy_mode;
> > +     spx5_port->conf.speed = SPEED_UNKNOWN;
> > +     spx5_port->conf.power_down = true;
> > +     sparx5->ports[portno] = spx5_port;
>
>
> > +struct net_device *sparx5_create_netdev(struct sparx5 *sparx5, u32 portno)
> > +{
> > +     struct net_device *ndev;
> > +     struct sparx5_port *spx5_port;
> > +     int err;
> > +
> > +     ndev = devm_alloc_etherdev(sparx5->dev, sizeof(struct sparx5_port));
> > +     if (!ndev)
> > +             return ERR_PTR(-ENOMEM);
> > +
>
> ...
>
> > +     err = register_netdev(ndev);
> > +     if (err) {
> > +             dev_err(sparx5->dev, "netdev registration failed\n");
> > +             return ERR_PTR(err);
> > +     }
>
> This is one of the classic bugs in network drivers. As soon as you
> call register_netdev() the interface is live. The network stack can
> start using it. But you have not finished initialzing spx5_port. So
> bad things are going to happen.

Oops.  I will fix that.

Thanks for the comments.
Steen
>    Andrew

BR
Steen

---------------------------------------
Steen Hegelund
steen.hegelund@xxxxxxxxxxxxx