[PATCH 4.14 02/99] net: phy: Avoid multiple suspends

From: Greg Kroah-Hartman
Date: Thu Mar 19 2020 - 09:32:55 EST


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

commit 503ba7c6961034ff0047707685644cad9287c226 upstream.

It is currently possible for a PHY device to be suspended as part of a
network device driver's suspend call while it is still being attached to
that net_device, either via phy_suspend() or implicitly via phy_stop().

Later on, when the MDIO bus controller get suspended, we would attempt
to suspend again the PHY because it is still attached to a network
device.

This is both a waste of time and creates an opportunity for improper
clock/power management bugs to creep in.

Fixes: 803dd9c77ac3 ("net: phy: avoid suspending twice a PHY")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/phy/phy_device.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -91,7 +91,7 @@ static bool mdio_bus_phy_may_suspend(str
* MDIO bus driver and clock gated at this point.
*/
if (!netdev)
- return !phydev->suspended;
+ goto out;

/* Don't suspend PHY if the attached netdev parent may wakeup.
* The parent may point to a PCI device, as in tg3 driver.
@@ -106,7 +106,8 @@ static bool mdio_bus_phy_may_suspend(str
if (device_may_wakeup(&netdev->dev))
return false;

- return true;
+out:
+ return !phydev->suspended;
}

static int mdio_bus_phy_suspend(struct device *dev)