net: phy: lan87xx: fix access to wrong register of LAN87xx

stable inclusion
from stable-5.10.37
commit c45cb22a5500c6f45fa6e966400f6afd51e685ad
bugzilla: 51868
CVE: NA

--------------------------------

[ Upstream commit fdb5cc6a ]

The function lan87xx_config_aneg_ext was introduced to configure
LAN95xxA but as well writes to undocumented register of LAN87xx.
This fix prevents that access.

The function lan87xx_config_aneg_ext gets more suitable for the new
behavior name.
Reported-by: NMåns Rullgård <mans@mansr.com>
Fixes: 05b35e7e ("smsc95xx: add phylib support")
Signed-off-by: NAndre Edich <andre.edich@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/phy/smsc.c

@@ -152,10 +152,13 @@ static int lan87xx_config_aneg(struct phy_device *phydev)
 	return genphy_config_aneg(phydev);
 }
 
-static int lan87xx_config_aneg_ext(struct phy_device *phydev)
+static int lan95xx_config_aneg_ext(struct phy_device *phydev)
 {
 	int rc;
 
+	if (phydev->phy_id != 0x0007c0f0) /* not (LAN9500A or LAN9505A) */
+		return lan87xx_config_aneg(phydev);
+
 	/* Extend Manual AutoMDIX timer */
 	rc = phy_read(phydev, PHY_EDPD_CONFIG);
 	if (rc < 0)
@@ -408,7 +411,7 @@ static struct phy_driver smsc_phy_driver[] = {
 	.read_status	= lan87xx_read_status,
 	.config_init	= smsc_phy_config_init,
 	.soft_reset	= smsc_phy_reset,
-	.config_aneg	= lan87xx_config_aneg_ext,
+	.config_aneg	= lan95xx_config_aneg_ext,
 
 	/* IRQ related */
 	.ack_interrupt	= smsc_phy_ack_interrupt,