+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 = {};
+	int ret;
+
+	if (!tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL])
+		return -EINVAL;

I would make use of extack here, and report what is missing.

+
+	config.admin_cotrol = nla_get_u8(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);

It would be good to have some basic validation here, make sure user
space has passed a reasonable value.

You should also define what 0 and
ETHTOOL_A_PODL_PSE_ADMIN_CONTROL_UNKNOWN means here when passed in. In
future, there could be additional things which could be configured, so
struct pse_control_config gets additional members.
ETHTOOL_A_PODL_PSE_ADMIN_CONTROL appears to be mandatory, you return
-EVINAL if missing, so if you don't want to change it, but change some
other new thing, maybe 0 should be passed here? And the driver should
not consider it an error?  ETHTOOL_A_PODL_PSE_ADMIN_CONTROL_UNKNOWN
however seems invalid and so should be rejected here?

	Andrew