Subject: [PATCH net-next] net: phy: lan87xx: fix access to wrong register of LAN87xx

From: Andre Edich <[email-masked]>
Date: Mon, 29 Mar 2021 11:45:36 +0200

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: Måns Rullgård <[email-masked]>
Fixes: 05b35e7eb9a1 ("smsc95xx: add phylib support")
Signed-off-by: Andre Edich <[email-masked]>
---
 drivers/net/phy/smsc.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index ddb78fb4d6dc..d8cac02a79b9 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -185,10 +185,13 @@ 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)
@@ -441,7 +444,7 @@ 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 */
 	.config_intr	= smsc_phy_config_intr,
-- 
2.28.0