net: phy: fix save wrong speed and duplex problem if autoneg is on

stable inclusion
from stable-5.10.24
commit 6aa23829949c2c0912e82866aeab4fd591595235
bugzilla: 51348

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

commit d9032dba upstream.

If phy uses generic driver and autoneg is on, enter command
"ethtool -s eth0 speed 50" will not change phy speed actually, but
command "ethtool eth0" shows speed is 50Mb/s because phydev->speed
has been set to 50 and no update later.

And duplex setting has same problem too.

However, if autoneg is on, phy only changes speed and duplex according to
phydev->advertising, but not phydev->speed and phydev->duplex. So in this
case, phydev->speed and phydev->duplex don't need to be set in function
phy_ethtool_ksettings_set() if autoneg is on.

Fixes: 51e2a384 ("PHY: Avoid unnecessary aneg restarts")
Signed-off-by: NGuangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/phy/phy.c

@@ -293,14 +293,16 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev,
 
 	phydev->autoneg = autoneg;
 
-	phydev->speed = speed;
+	if (autoneg == AUTONEG_DISABLE) {
+		phydev->speed = speed;
+		phydev->duplex = duplex;
+	}
 
 	linkmode_copy(phydev->advertising, advertising);
 
 	linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
 			 phydev->advertising, autoneg == AUTONEG_ENABLE);
 
-	phydev->duplex = duplex;
 	phydev->master_slave_set = cmd->base.master_slave_cfg;
 	phydev->mdix_ctrl = cmd->base.eth_tp_mdix_ctrl;