Re: [PATCH net-next 5/5] net: dsa: split dsa_port's netdev member

[Florian Fainelli]

On 10/12/2017 03:51 PM, Vivien Didelot wrote:
> The dsa_port structure has a "netdev" member, which can be used for
> either the master device, or the slave device, depending on its type.
> 
> It is true that today, CPU port are not exposed to userspace, thus the
> port's netdev member can be used to point to its master interface.
> 
> But it is still slightly confusing, so split it into more explicit
> "master" and "slave" members.

I do see some value in doing that, although I also see value in having
structure members be named after what they are, rather than their use
(oh well, it's all debatable anyway), see below for a suggestion on how
to reconcile the two:

>  struct dsa_port {
> +	/* Master device, physically connected if this is a CPU port */
> +	struct net_device *master;
> +
> +	/* Slave device, if this port is exposed to userspace */
> +	struct net_device *slave;
> +

How about using:

	union {
		struct net_device *master;
		struct net_device *slave;
	} netdev;

Such that this serves both purposes of clearly communicating what the
structure member is, and it can be either one of the two, but not both
at the same time?

-- 
Florian