+int ksz9477_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr,
+		     struct dsa_port *partner)
+{
+	struct ksz_device *dev = ds->priv;
+	struct net_device *slave;
+	u8 i, data;
+	int ret;
+
+	/* Program which ports shall support HSR */
+	dev->hsr_ports = BIT(port) | BIT(partner->index);
+	ksz_write32(dev, REG_HSR_PORT_MAP__4, dev->hsr_ports);
+
+	/* Enable discarding of received HSR frames */
+	ksz_read8(dev, REG_HSR_ALU_CTRL_0__1, &data);
+	data |= HSR_DUPLICATE_DISCARD;
+	data &= ~HSR_NODE_UNICAST;
+	ksz_write8(dev, REG_HSR_ALU_CTRL_0__1, data);
+
+	/* Self MAC address filtering for HSR frames to avoid
+	 * traverse of the HSR ring more than once.
+	 *
+	 * The HSR port (i.e. hsr0) MAC address is used.
+	 */
+	if (!is_valid_ether_addr(hsr->dev_addr)) {
+		dev_err(dev->dev,
+			"Set valid MAC address to %s for HSR operation!",
+			hsr->name);
+		return -EINVAL;
+	}

This seems like something which should be done at a higher level, not
per driver. Please check if there is an existing test, and if not, add
one in the HSR core.

    Andrew