smsc9420: prevent BUG() if ethtool is called with interface down
This patch fixes a null pointer dereference BUG() if ethtool is used on
an smsc9420 interface while it is down, because the phy_dev is only
allocated while the interface is up.
Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/smsc9420.c b/drivers/net/smsc9420.c
index b4909a2..0f79092 100644
--- a/drivers/net/smsc9420.c
+++ b/drivers/net/smsc9420.c
@@ -252,6 +252,9 @@
{
struct smsc9420_pdata *pd = netdev_priv(dev);
+ if (!pd->phy_dev)
+ return -ENODEV;
+
cmd->maxtxpkt = 1;
cmd->maxrxpkt = 1;
return phy_ethtool_gset(pd->phy_dev, cmd);
@@ -262,6 +265,9 @@
{
struct smsc9420_pdata *pd = netdev_priv(dev);
+ if (!pd->phy_dev)
+ return -ENODEV;
+
return phy_ethtool_sset(pd->phy_dev, cmd);
}
@@ -290,6 +296,10 @@
static int smsc9420_ethtool_nway_reset(struct net_device *netdev)
{
struct smsc9420_pdata *pd = netdev_priv(netdev);
+
+ if (!pd->phy_dev)
+ return -ENODEV;
+
return phy_start_aneg(pd->phy_dev);
}
@@ -312,6 +322,10 @@
for (i = 0; i < 0x100; i += (sizeof(u32)))
data[j++] = smsc9420_reg_read(pd, i);
+ // cannot read phy registers if the net device is down
+ if (!phy_dev)
+ return;
+
for (i = 0; i <= 31; i++)
data[j++] = smsc9420_mii_read(phy_dev->bus, phy_dev->addr, i);
}