From: Heiner Kallweit <hkallweit1@xxxxxxxxx> [ Upstream commit aa6b1956158f1afc52761137620d4b3f8a058d24 ] 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 <liuyonglong@xxxxxxxxxx> Tested-by: liuyonglong <liuyonglong@xxxxxxxxxx> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/phy/phy_device.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1730,6 +1730,12 @@ done: 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);
