Re: [PATCH] net/cadence/macb: fix kernel Oops if no PHY were discoveredduring probe

[boris brezillon]

Hello Bo,

On 26/08/2013 11:09, Bo Shen wrote:
> Hi Boris,
>
> On 08/25/2013 03:21 AM, Boris BREZILLON wrote:
> > Test the presence of a PHY device before printing attached PHY
> > informations.
> >
> > Signed-off-by: Boris BREZILLON <b.brezillon@xxxxxxxxxxx>
> > ---
> >   drivers/net/ethernet/cadence/macb.c |    6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/cadence/macb.c 
> > b/drivers/net/ethernet/cadence/macb.c
> > index e866608..fd3b67f 100644
> > --- a/drivers/net/ethernet/cadence/macb.c
> > +++ b/drivers/net/ethernet/cadence/macb.c
> > @@ -1868,8 +1868,10 @@ static int __init macb_probe(struct 
> > platform_device *pdev)
> >               dev->irq, dev->dev_addr);
> >
> >       phydev = bp->phy_dev;
> > -    netdev_info(dev, "attached PHY driver [%s] (mii_bus:phy_addr=%s, 
> > irq=%d)\n",
> > -            phydev->drv->name, dev_name(&phydev->dev), phydev->irq);
> > +    if (phydev)
> > +        netdev_info(dev, "attached PHY driver [%s] 
> > (mii_bus:phy_addr=%s, irq=%d)\n",
> > +                phydev->drv->name, dev_name(&phydev->dev),
> > +                phydev->irq);
>
> Actually no need this check, if PHY is attached failed, the macb 
> driver probe will fail, then it won't show this message.

You're right (thanks for pointing this out).
Indeed this is a bug I introduced in this patch series ( 
https://lkml.org/lkml/2013/8/22/381).

In macb_mii_init function, the err field may be set to 0 (instead of the 
default -ENXIO value) if no PHY
is discovered.
As macb_mii_probe return code is not copied to err, this result in a 0 
return even if macb_mii_probe
failed.

Nicolas, forget about this patch, I'll fix this in the appropriate patch 
series (except if you plan to add
dynamic MAC/PHY association, and treat missing PHY during probe process 
as an acceptable result :-)).

Best Regards,

Boris BREZILLON

> >       return 0;
>
> Best Regards,
> Bo Shen

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