Re: [PATCH net v1 1] net: macb: Avoid 20s boot delay by skipping MDIO bus registration for fixed-link PHY

[Andrew Lunn]

> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index f06babec04a0b..e4ee55bc53ba7 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -930,9 +930,6 @@ static int macb_mdiobus_register(struct macb *bp)
>  		return ret;
>  	}
> 
> -	if (of_phy_is_fixed_link(np))
> -		return mdiobus_register(bp->mii_bus);
> -
>  	/* Only create the PHY from the device tree if at least one PHY is
>  	 * described. Otherwise scan the entire MDIO bus. We do this to support
>  	 * old device tree that did not follow the best practices and did not
> @@ -953,8 +950,19 @@ static int macb_mdiobus_register(struct macb *bp)
> 
>  static int macb_mii_init(struct macb *bp)
>  {
> +	struct device_node *child, *np = bp->pdev->dev.of_node;
>  	int err = -ENXIO;
> 
> +	/* With fixed-link, we don't need to register the MDIO bus,
> +	 * except if we have a child named "mdio" in the device tree.
> +	 * In that case, some PHYs may be attached to the MACB's MDIO bus.

nitpick. It could be a switch on the MDIO bus, so "some devices may
be"

> +	 */
> +	child = of_get_child_by_name(np, "mdio");
> +	if (child)
> +		of_node_put(child);

The code now gets this node twice. You could add an optimisation patch
which passed child to macb_mdiobus_register().

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew