Re: [PATCH net] net: phy: fix save wrong speed and duplex problem if autoneg is on

From: Huazhong Tan
Date: Fri Feb 26 2021 - 20:30:29 EST



On 2021/2/27 7:56, Jakub Kicinski wrote:
On Fri, 26 Feb 2021 15:44:42 +0800 Huazhong Tan wrote:
From: Guangbin Huang <huangguangbin2@xxxxxxxxxx>

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.
Can we get a Fixes tag for this one? How far back does this behavior
date?
will add a fixes tag in V2, thanks.
.