linux-kernel - [PATCH 5.4 057/123] net: phy: Avoid multiple suspends

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Date:   Tue, 17 Mar 2020 11:54:44 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 5.4 057/123] net: phy: Avoid multiple suspends

From: Florian Fainelli <f.fainelli@...il.com>

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@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 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
@@ -246,7 +246,7 @@ static bool mdio_bus_phy_may_suspend(str
 	 * MDIO bus driver and clock gated at this point.
 	 */
 	if (!netdev)
-		return !phydev->suspended;
+		goto out;

 	if (netdev->wol_enabled)
 		return false;
@@ -266,7 +266,8 @@ 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)