+static int qca808x_fifo_reset(struct phy_device *phydev)
+{
+	/* Reset serdes fifo on link down, Release serdes fifo on link up,
+	 * the serdes address is phy address added by 1.
+	 */
+	return mdiobus_c45_modify_changed(phydev->mdio.bus, phydev->mdio.addr + 1,
+			MDIO_MMD_PMAPMD, QCA8081_PHY_SERDES_MMD1_FIFO_CTRL,
+			QCA8081_PHY_FIFO_RSTN, phydev->link ? QCA8081_PHY_FIFO_RSTN : 0);

In polling mode, this is going to be called once per second. Do you
really want to be setting that register all the time? Consider using
the link_change_notify callback.

Also, can you tell us more about this SERDES device on the bus. I just
want to make sure this is not a PCS and should have its own driver.

     Andrew