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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-08-25 09:49:47 +0100
committerDavid S. Miller <davem@davemloft.net>2015-08-25 16:30:46 -0700
commit05a7f582be961824d62a7f4a817f3783148b5f8a (patch)
treed43da7ed68308ae9b606d7ad681f5789c1956acd /drivers/net/phy/phy.c
parentbef0057b7ba881d5ae67eec876df7a26fe672a59 (diff)
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>
Diffstat (limited to 'drivers/net/phy/phy.c')
-rw-r--r--drivers/net/phy/phy.c16
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);
}