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

From: Guenter Roeck <[email-masked]>
Date: Fri, 12 Jun 2015 11:29:57 -0700

On 06/12/2015 11:14 AM, Florian Fainelli wrote:
> 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?
>

If so, should that be done in a separate patch set ?

Guenter