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Date:   Mon, 5 Dec 2022 09:28:51 +0000
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, Oleksij Rempel <o.rempel@pengutronix.de>
Subject: Re: [PATCH v2 net-next 1/4] net/ethtool: add netlink interface for
 the PLCA RS
Message-ID: <Y42509XkIN1S73Er@shell.armlinux.org.uk>
References: <fc3ac4f2d0c28d9c24b909e97791d1f784502a4a.1670204277.git.piergiorgio.beruto@gmail.com>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Mon, Dec 05, 2022 at 02:41:35AM +0100, Piergiorgio Beruto wrote:
> +int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
> +{
> +	struct ethnl_req_info req_info = {};
> +	struct nlattr **tb = info->attrs;
> +	const struct ethtool_phy_ops *ops;
> +	struct phy_plca_cfg plca_cfg;
> +	struct net_device *dev;
> +
> +	bool mod = false;
> +	int ret;
> +
> +	ret = ethnl_parse_header_dev_get(&req_info,
> +					 tb[ETHTOOL_A_PLCA_HEADER],
> +					 genl_info_net(info), info->extack,
> +					 true);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev = req_info.dev;
> +
> +	// check that the PHY device is available and connected
> +	if (!dev->phydev) {
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}

This check should really be done under the RTNL lock. phydevs can come
and go with SFP cages.

> +
> +	rtnl_lock();

-- 
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