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 11:03:42 -0700

Hi Florian,

On 06/12/2015 10:18 AM, 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.
>
> 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;
> +
How does cpu_port_mask interact / interfer / coexist with dst->cpu_port
and dsa_is_cpu_port() ?

Elsewhere we have
	if (dsa_is_cpu_port(ds, p) || ds->dsa_port_mask & (1 << p))
so I don't entirely see why we need to add cpu_port_mask at this time.
Shouldn't that be a separate patch, maybe with a new macro / function
to check if the port is a cpu port or an external switch port ?

Thanks,
Guenter