|author||Florian Fainelli <email@example.com>||2015-01-26 22:05:40 -0800|
|committer||David S. Miller <firstname.lastname@example.org>||2015-01-27 00:16:51 -0800|
net: phy: avoid suspending twice a PHY
As part of a call to ndo_close() a netdevice driver may call phy_disconnect() -> phy_detach() -> phy_suspend(), such that the PHY is suspsended at this point and a netdevice driver may clock gate the backing peripheral providing MDIO bus accessses as well. Update mdio_bus_phy_may_suspend() to return whether a PHY is allowed to be suspended and conversely resumed if and only if it was not previously suspended before while it is currently in detached (netdev pointer is NULL) state. This fixes bus errors seen during S2/S3 suspend/resume cycles for netdevice drivers such as GENET which clock gates the entire Ethernet MAC, including the MDIO bus block. Acked-by: Fugang Duan <B38611@freescale.com> Tested-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Florian Fainelli <email@example.com> Signed-off-by: David S. Miller <firstname.lastname@example.org>
Diffstat (limited to 'drivers/net/phy/mdio_bus.c')
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 20447741893a..095ef3fe369a 100644
@@ -443,9 +443,13 @@ static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
if (!drv || !phydrv->suspend)
- /* PHY not attached? May suspend. */
+ /* PHY not attached? May suspend if the PHY has not already been
+ * suspended as part of a prior call to phy_disconnect() ->
+ * phy_detach() -> phy_suspend() because the parent netdev might be the
+ * MDIO bus driver and clock gated at this point.
- return true;
+ return !phydev->suspended;
/* Don't suspend PHY if the attched netdev parent may wakeup.
* The parent may point to a PCI device, as in tg3 driver.