Le 08/25/15 01:49, Russell King a écrit :
> 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.
>
> Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
Acked-by: Florian Fainelli <f.faine...@gmail.com>
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")
Thanks!
> ---
> drivers/net/phy/phy.c | 16 ++++++++++++----
> 1 file 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);
> }
>
--
Florian
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
