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| author | Heiner Kallweit <hkallweit1@gmail.com> | 2019-07-31 23:05:10 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-08-02 18:16:04 -0700 |
| commit | aa6b1956158f1afc52761137620d4b3f8a058d24 (patch) | |
| tree | ae2e398a615a9348ca4833f94ac395bae875719c /drivers/net/phy/phy_device.c | |
| parent | 2802d2cf24b1ca7ea4c54dde266ded6a16020eb5 (diff) | |
| download | lwn-aa6b1956158f1afc52761137620d4b3f8a058d24.tar.gz lwn-aa6b1956158f1afc52761137620d4b3f8a058d24.zip | |
net: phy: fix race in genphy_update_link
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@huawei.com>
Tested-by: liuyonglong <liuyonglong@huawei.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy/phy_device.c')
| -rw-r--r-- | drivers/net/phy/phy_device.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 6b5cb87f3866..7ddd91df99e3 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1774,6 +1774,12 @@ 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); |