Subject: Re: [PATCH 3/3] net: dsa: Allow configuration of CPU & DSA port speeds/duplex

From: Florian Fainelli <[email-masked]>
Date: Fri, 12 Jun 2015 11:14:25 -0700

On 12/06/15 10:18, Andrew Lunn wrote:
> By default, DSA and CPU ports are configured to the maximum speed the
> switch supports. However there can be use cases where the peer device
> port is slower. Allow a fixed-link property to be used with the DSA
> and CPU port in the device tree, and use this information to configure
> the port.

Humm, I suppose this means that we might end-up with two fixed PHY
devices, one for the Ethernet MAC, and another one for the switch? That
might duplicate the same information, though I cannot think of a better
solution than using phandles to resolve that.

> 
> Signed-off-by: Andrew Lunn <[email-masked]>
> ---
>  include/net/dsa.h |  1 +
>  net/dsa/dsa.c     | 39 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index fbca63ba8f73..24572f99224c 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -160,6 +160,7 @@ struct dsa_switch {
>  	 * Slave mii_bus and devices for the individual ports.
>  	 */
>  	u32			dsa_port_mask;
> +	u32			cpu_port_mask;
>  	u32			phys_port_mask;
>  	u32			phys_mii_mask;
>  	struct mii_bus		*slave_mii_bus;
> diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
> index 392e29a0227d..f9c8f4e7ebce 100644
> --- a/net/dsa/dsa.c
> +++ b/net/dsa/dsa.c
> @@ -176,6 +176,36 @@ __ATTRIBUTE_GROUPS(dsa_hwmon);
>  #endif /* CONFIG_NET_DSA_HWMON */
>  
>  /* basic switch operations **************************************************/
> +static int dsa_cpu_dsa_setup(struct dsa_switch *ds, struct net_device *master)
> +{
> +	struct dsa_chip_data *cd = ds->pd;
> +	struct device_node *port_dn;
> +	struct phy_device *phydev;
> +	int ret, port;
> +
> +	for (port = 0; port < DSA_MAX_PORTS; port++) {
> +		if (!((ds->cpu_port_mask | ds->dsa_port_mask) & (1 << port)))
> +			continue;
> +
> +		port_dn = cd->port_dn[port];
> +		if (of_phy_is_fixed_link(port_dn)) {
> +			ret = of_phy_register_fixed_link(port_dn);
> +			if (ret) {
> +				netdev_err(master,
> +					   "failed to register fixed PHY\n");
> +				return ret;
> +			}
> +			phydev = of_phy_find_device(port_dn);
> +			phydev->is_pseudo_fixed_link = true;
> +			genphy_config_init(phydev);
> +			genphy_read_status(phydev);

I was curious as to why you were doing this at first, but I guess this
is because the PHY state machine is not started for this fixed PHY that
you just created, right?

> +			if (ds->drv->adjust_link)
> +				ds->drv->adjust_link(ds, port, phydev);
> +		}
> +	}
> +	return 0;
> +}
> +
>  static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
>  {
>  	struct dsa_switch_driver *drv = ds->drv;
> @@ -204,6 +234,7 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
>  			}
>  			dst->cpu_switch = index;
>  			dst->cpu_port = i;
> +			ds->cpu_port_mask |= 1 << i;

Same question as Guenter here, I assume this is because you plan on
having multiple CPU ports connected to the switch and this makes it
easier to deal with, is that right?

>  		} else if (!strcmp(name, "dsa")) {
>  			ds->dsa_port_mask |= 1 << i;
>  		} else {
> @@ -297,6 +328,14 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
>  		}
>  	}
>  
> +	/* Perform configuration of the CPU and DSA ports */
> +	ret = dsa_cpu_dsa_setup(ds, dst->master_netdev);
> +	if (ret < 0) {
> +		netdev_err(dst->master_netdev, "[%d] : can't configure CPU and DSA ports\n",
> +			   index);
> +		ret = 0;
> +	}
> +
>  #ifdef CONFIG_NET_DSA_HWMON
>  	/* If the switch provides a temperature sensor,
>  	 * register with hardware monitoring subsystem.
> 

-- 
Florian