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authorHeiner Kallweit2019-07-31 23:05:10 +0200
committerDavid S. Miller2019-08-02 18:16:04 -0700
commitaa6b1956158f1afc52761137620d4b3f8a058d24 (patch)
treeae2e398a615a9348ca4833f94ac395bae875719c /drivers/net/phy/phy_device.c
parent2802d2cf24b1ca7ea4c54dde266ded6a16020eb5 (diff)
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.c6
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);