diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-08-25 11:49:47 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-08-26 02:30:46 +0300 |
| commit | 05a7f582be961824d62a7f4a817f3783148b5f8a (patch) | |
| tree | d43da7ed68308ae9b606d7ad681f5789c1956acd | |
| parent | bef0057b7ba881d5ae67eec876df7a26fe672a59 (diff) | |
| download | linux-05a7f582be961824d62a7f4a817f3783148b5f8a.tar.xz | |
net: phy: add locking to phy_read_mmd_indirect()/phy_write_mmd_indirect()
The phy layer is missing locking for the above two functions - it
has been observed that two threads (userspace and the phy worker
thread) can race, entering the bus ->write or ->read functions
simultaneously.
This causes the FEC driver to initialise a completion while another
thread is waiting on it or while the interrupt is calling complete()
on it, which causes spinlock unlock-without-lock, spinlock lockups,
and completion timeouts.
Fixes: a59a4d192 ("phy: add the EEE support and the way to access to the MMD registers.")
Fixes: 0c1d77dfb ("net: libphy: Add phy specific function to access mmd phy registers")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/phy/phy.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 1e1fbb049ec6..34fe339f4e80 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -1038,10 +1038,14 @@ int phy_read_mmd_indirect(struct phy_device *phydev, int prtad, int value = -1; if (phydrv->read_mmd_indirect == NULL) { - mmd_phy_indirect(phydev->bus, prtad, devad, addr); + struct mii_bus *bus = phydev->bus; + + mutex_lock(&bus->mdio_lock); + mmd_phy_indirect(bus, prtad, devad, addr); /* Read the content of the MMD's selected register */ - value = phydev->bus->read(phydev->bus, addr, MII_MMD_DATA); + value = bus->read(bus, addr, MII_MMD_DATA); + mutex_unlock(&bus->mdio_lock); } else { value = phydrv->read_mmd_indirect(phydev, prtad, devad, addr); } @@ -1071,10 +1075,14 @@ void phy_write_mmd_indirect(struct phy_device *phydev, int prtad, struct phy_driver *phydrv = phydev->drv; if (phydrv->write_mmd_indirect == NULL) { - mmd_phy_indirect(phydev->bus, prtad, devad, addr); + struct mii_bus *bus = phydev->bus; + + mutex_lock(&bus->mdio_lock); + mmd_phy_indirect(bus, prtad, devad, addr); /* Write the data into MMD's selected register */ - phydev->bus->write(phydev->bus, addr, MII_MMD_DATA, data); + bus->write(bus, addr, MII_MMD_DATA, data); + mutex_unlock(&bus->mdio_lock); } else { phydrv->write_mmd_indirect(phydev, prtad, devad, addr, data); } |