FAILED: patch "[PATCH] net: phy: fix save wrong speed and duplex problem if autoneg" failed to apply to 4.19-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d9032dba5a2b2bbf0fdce67c8795300ec9923b43 Mon Sep 17 00:00:00 2001
From: Guangbin Huang <huangguangbin2@huawei.com>
Date: Sat, 27 Feb 2021 11:05:58 +0800
Subject: [PATCH] net: phy: fix save wrong speed and duplex problem if autoneg
 is on

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: 51e2a3846eab ("PHY: Avoid unnecessary aneg restarts")
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 1be07e45d314..fc2e7cb5b2e5 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -276,14 +276,16 @@ 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;