linux-kernel - [PATCH 4.9 03/90] net: phy: Avoid multiple suspends

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200319123929.561337351@linuxfoundation.org>
Date:   Thu, 19 Mar 2020 13:59:25 +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 4.9 03/90] 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
@@ -95,7 +95,7 @@ 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.
@@ -110,7 +110,8 @@ 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)