phy: phy_start_aneg: Add an unlocked version

Split phy_start_aneg into a wrapper which takes the PHY lock, and a
helper doing the real work. This will be needed when
phy_ethtook_ksettings_set takes the lock.

Fixes: 2d55173 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -700,33 +700,51 @@ static int phy_check_link_status(struct phy_device *phydev)
 }
 
 /**
- * phy_start_aneg - start auto-negotiation for this PHY device
+ * _phy_start_aneg - start auto-negotiation for this PHY device
  * @phydev: the phy_device struct
  *
  * Description: Sanitizes the settings (if we're not autonegotiating
  *   them), and then calls the driver's config_aneg function.
  *   If the PHYCONTROL Layer is operating, we change the state to
  *   reflect the beginning of Auto-negotiation or forcing.
  */
-int phy_start_aneg(struct phy_device *phydev)
+static int _phy_start_aneg(struct phy_device *phydev)
 {
 	int err;
 
+	lockdep_assert_held(&phydev->lock);
+
 	if (!phydev->drv)
 		return -EIO;
 
-	mutex_lock(&phydev->lock);
-
 	if (AUTONEG_DISABLE == phydev->autoneg)
 		phy_sanitize_settings(phydev);
 
 	err = phy_config_aneg(phydev);
 	if (err < 0)
-		goto out_unlock;
+		return err;
 
 	if (phy_is_started(phydev))
 		err = phy_check_link_status(phydev);
-out_unlock:
+
+	return err;
+}
+
+/**
+ * phy_start_aneg - start auto-negotiation for this PHY device
+ * @phydev: the phy_device struct
+ *
+ * Description: Sanitizes the settings (if we're not autonegotiating
+ *   them), and then calls the driver's config_aneg function.
+ *   If the PHYCONTROL Layer is operating, we change the state to
+ *   reflect the beginning of Auto-negotiation or forcing.
+ */
+int phy_start_aneg(struct phy_device *phydev)
+{
+	int err;
+
+	mutex_lock(&phydev->lock);
+	err = _phy_start_aneg(phydev);
 	mutex_unlock(&phydev->lock);
 
 	return err;