In phy_start_aneg() autoneg is started, and immediately after that link and autoneg status are read. As reported in [0] it can happen that at time of this read the PHY has reset the "aneg complete" bit but not yet the "link up" bit, what can result in a false link-up detection. To fix this don't report link as up if we're in aneg mode and PHY doesn't signal "aneg complete".
[0] https://marc.info/?t=156413509900003&r=1&w=2 Fixes: 4950c2ba49cc ("net: phy: fix autoneg mismatch case in genphy_read_status") Reported-by: liuyonglong <liuyongl...@huawei.com> Tested-by: liuyonglong <liuyongl...@huawei.com> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com> --- drivers/net/phy/phy_device.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 6b5cb87f3..7ddd91df9 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1774,6 +1774,12 @@ int genphy_update_link(struct phy_device *phydev) phydev->link = status & BMSR_LSTATUS ? 1 : 0; phydev->autoneg_complete = status & BMSR_ANEGCOMPLETE ? 1 : 0; + /* Consider the case that autoneg was started and "aneg complete" + * bit has been reset, but "link up" bit not yet. + */ + if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete) + phydev->link = 0; + return 0; } EXPORT_SYMBOL(genphy_update_link); -- 2.22.0
