Subject: Re: [PATCH net-next v2 6/7] ethtool: add interface to interact with Ethernet Power Equipment

From: Jakub Kicinski <[email-masked]>
Date: Thu, 25 Aug 2022 11:07:56 -0700

On Thu, 25 Aug 2022 15:02:10 +0200 Oleksij Rempel wrote:
> +void ethtool_set_ethtool_pse_ops(const struct ethtool_pse_ops *ops)
> +{
> +	rtnl_lock();
> +	ethtool_pse_ops = ops;
> +	rtnl_unlock();
> +}
> +EXPORT_SYMBOL_GPL(ethtool_set_ethtool_pse_ops);

Do we really need the loose linking on the PSE ops?
It's not a lot of code, and the pcdev->ops should be 
enough to decouple drivers, it seems.

> +static int pse_set_pse_config(struct net_device *dev,
> +			      struct netlink_ext_ack *extack,
> +			      struct nlattr **tb)
> +{
> +	struct phy_device *phydev = dev->phydev;
> +	struct pse_control_config config = {};
> +	const struct ethtool_pse_ops *ops;
> +	int ret;
> +
> +	if (!tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL])
> +		return 0;

If SET has no useful attrs the usual response is -EINVAL.

> +	ops = ethtool_pse_ops;
> +	if (!ops || !ops->set_config)
> +		return -EOPNOTSUPP;
> +
> +	config.admin_cotrol = nla_get_u8(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);
> +
> +	if (!phydev)
> +		return -EOPNOTSUPP;
> +
> +	// todo resolve phydev dependecy

My lack of phydev understanding and laziness are likely the cause,
but I haven't found an explanation for this todo. What is it about?

> +	if (!phydev->psec)
> +		ret = -EOPNOTSUPP;
> +	else
> +		ret = ops->set_config(phydev->psec, extack, &config);
> +
> +	return ret;
> +}