Re: [PATCH net-next v2 08/10] net: dsa: Add support for platform data

From: Andrew Lunn
Date: Fri Jan 13 2017 - 09:11:22 EST


> static int _dsa_register_switch(struct dsa_switch *ds, struct device *dev)
> {
> + struct dsa_chip_data *pdata = dev->platform_data;
> struct device_node *np = dev->of_node;
> struct dsa_switch_tree *dst;
> struct device_node *ports;
> u32 tree, index;
> int i, err;
>
> - err = dsa_parse_member_dn(np, &tree, &index);
> - if (err)
> - return err;
> + if (np) {
> + err = dsa_parse_member_dn(np, &tree, &index);
> + if (err)
> + return err;
>
> - ports = dsa_get_ports(ds, np);
> - if (IS_ERR(ports))
> - return PTR_ERR(ports);
> + ports = dsa_get_ports(ds, np);
> + if (IS_ERR(ports))
> + return PTR_ERR(ports);
>
> - err = dsa_parse_ports_dn(ports, ds);
> - if (err)
> - return err;
> + err = dsa_parse_ports_dn(ports, ds);
> + if (err)
> + return err;
> + } else {
> + err = dsa_parse_member(pdata, &tree, &index);

Hi Florian

Maybe it is hiding, but i don't see anywhere you check that pdata !=
NULL.

At least for x86 platforms, i don't expect we are booting using
platform data like ARM systems used to do. I think it is more likely a
glue module will be loaded. It looks up the MDIO bus and appends a
platform data to an MDIO device. The switch driver then needs to load
and use the platform data. But if things happen in a different order,
it could be the switch driver probes before the glue driver, meaning
pdata is NULL.

Do we even want to return -EPROBE_DEFERED?

Andrew