[PATCH] staging: octeon-ethernet: trivial: Avoid OOPS if phydev is not set

[Aaro Koskinen]

Hi,

On Mon, Oct 14, 2013 at 01:10:51PM +0300, Dan Carpenter wrote:
> On Sun, Oct 13, 2013 at 02:28:10PM -0700, Greg KH wrote:
> > On Sun, Oct 13, 2013 at 08:59:54PM +0200, Sebastian Pöhn wrote:
> > > A zero pointer deref on priv->phydev->link was causing oops on our systems.
> > > Might be related to improper configuration but we should fail gracefully here ;-)
> > > 
> > > Signed-off-by: Sebastian Poehn <sebastian.poehn at googlemail.com>
> > > 
> > > ---
> > > 
> > > diff --git a/drivers/staging/octeon/ethernet-mdio.c b/drivers/staging/octeon/ethernet-mdio.c
> > > index 83b1030..bc8c503 100644
> > > --- a/drivers/staging/octeon/ethernet-mdio.c
> > > +++ b/drivers/staging/octeon/ethernet-mdio.c
> > > @@ -121,6 +121,9 @@ static void cvm_oct_adjust_link(struct net_device *dev)
> > >         struct octeon_ethernet *priv = netdev_priv(dev);
> > >         cvmx_helper_link_info_t link_info;
> > >  
> > > +       if(!priv->phydev)
> > > +               return ;
> > 
> > Please always run your patches through the scripts/checkpatch.pl tool so
> > that maintainers don't have to point out the obvious coding syle errors
> > by hand each time :)
> 
> Also it's whitespace damaged and doesn't apply.
> 
> > 
> > Care to try again?
> > 
> > Also, how was phydev NULL?  What was causing that?
> 
> To me it looks like phydev is always NULL.

It's initialized in cvm_oct_phy_setup_device():

	priv->phydev = of_phy_connect(dev, phy_node, cvm_oct_adjust_link, 0,
				      PHY_INTERFACE_MODE_GMII);

So maybe there is a chance that cvm_oct_adjust_link() callback gets called
already before the function returns? Getting a copy of the original OOPS
report/crash dump could help to confirm this.

A.