net: phy: avoid genphy_aneg_done() for PHYs without clause 22 support

BugLink: http://bugs.launchpad.net/bugs/1765010

[ Upstream commit 41408ad5 ]

Avoid calling genphy_aneg_done() for PHYs that do not implement the
Clause 22 register set.

Clause 45 PHYs may implement the Clause 22 register set along with the
Clause 22 extension MMD.  Hence, we can't simply block access to the
Clause 22 functions based on the PHY being a Clause 45 PHY.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/phy/phy.c

@@ -148,6 +148,12 @@ static inline int phy_aneg_done(struct phy_device *phydev)
 	if (phydev->drv->aneg_done)
 		return phydev->drv->aneg_done(phydev);
 
+	/* Avoid genphy_aneg_done() if the Clause 45 PHY does not
+	 * implement Clause 22 registers
+	 */
+	if (phydev->is_c45 && !(phydev->c45_ids.devices_in_package & BIT(0)))
+		return -EINVAL;
+
 	return genphy_aneg_done(phydev);
 }