If phydev->mii_ts is set by the PHY driver, it will always be
overwritten in of_mdiobus_register_phy(). Fix it. Also make sure, that
the unregister() doesn't do anything if the mii_timestamper was provided by
the PHY driver.
Fixes: 1dca22b18421 ("net: mdio: of: Register discovered MII time stampers.")
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
        struct mii_timestamping_desc *desc;
        struct list_head *this;
 
+       /* mii_timestamper statically registered by the PHY driver won't use the
+        * register_mii_timestamper() and thus don't have ->device set. Don't
+        * try to unregister these.
+        */
+       if (!mii_ts->device)
+               return;
+
        mutex_lock(&tstamping_devices_lock);
        list_for_each(this, &mii_timestamping_devices) {
                desc = list_entry(this, struct mii_timestamping_desc, list);
 
                of_node_put(child);
                return rc;
        }
-       phy->mii_ts = mii_ts;
+
+       /* phy->mii_ts may already be defined by the PHY driver. A
+        * mii_timestamper probed via the device tree will still have
+        * precedence.
+        */
+       if (mii_ts)
+               phy->mii_ts = mii_ts;
 
        dev_dbg(&mdio->dev, "registered phy %pOFn at address %i\n",
                child, addr);