From: Pavel Fedin
Date: Thu, 29 Oct 2015 06:45:22 +0000 (+0300)
Subject: net: smsc911x: Fix crash if loopback test fails
X-Git-Tag: firefly_0821_release~176^2~505^2~12^2~15
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b43c142f22236b37aa68faf23ac1bbd75f94c5b5;p=firefly-linux-kernel-4.4.55.git
net: smsc911x: Fix crash if loopback test fails
On certain hardware in certain situations loopback test fails and the
driver gets removed. During mdiobus_unregister() instance of PHY driver
gets disposed. But by this time it has already been started using
phy_connect_direct().
PHY driver uses DELAYED_WORK in order to maintain its state. Attempting
to dispose the driver without calling phy_disconnect() causes deallocation
of DELAYED_WORK being active. This shortly causes a bad crash in timer
code.
The problem can be discovered by enabling CONFIG_DEBUG_OBJECTS_TIMERS and
CONFIG_DEBUG_OBJECTS_FREE
Signed-off-by: Pavel Fedin
Signed-off-by: David S. Miller
---
diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index 3b4cd8a263de..c860c9007e49 100644
--- a/drivers/net/ethernet/smsc/smsc911x.c
+++ b/drivers/net/ethernet/smsc/smsc911x.c
@@ -1052,6 +1052,7 @@ static int smsc911x_mii_probe(struct net_device *dev)
#ifdef USE_PHY_WORK_AROUND
if (smsc911x_phy_loopbacktest(dev) < 0) {
SMSC_WARN(pdata, hw, "Failed Loop Back Test");
+ phy_disconnect(phydev);
return -ENODEV;
}
SMSC_TRACE(pdata, hw, "Passed Loop Back Test");