Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Sergei Shtylyov]

On 12/26/2015 11:07 PM, Julia Lawall wrote:

> > > > > > diff --git a/drivers/net/ethernet/ti/cpsw.c
> > > > > > b/drivers/net/ethernet/ti/cpsw.c
> > > > > > index 3409e80..6a76992 100644
> > > > > > --- a/drivers/net/ethernet/ti/cpsw.c
> > > > > > +++ b/drivers/net/ethernet/ti/cpsw.c
> > > > > > @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device
> > > > > > *pdev)
> > > > > >
> > > > > >         /* RX IRQ */
> > > > > >         irq = platform_get_irq(pdev, 1);
> > > > > > -    if (irq < 0)
> > > > > > +    if (irq < 0) {
> > > > > > +        ret = -ENOENT;
> > > > >
> > > > >      Why not just propagate an error returned by that function?
> > > >
> > > > OK, I did what was done a few lines before in the same function:
> > > >
> > > >           ndev->irq = platform_get_irq(pdev, 1);
> > > >           if (ndev->irq < 0) {
> > > >          dev_err(priv->dev, "error getting irq resource\n");
> > > >                   ret = -ENOENT;
> > > >                   goto clean_ale_ret;
> > > >           }
> > > >
> > > > Maybe they should all be changed?
> > >
> > >      Yeah, I'd vote for it. I'm seeing no sense in overriding an actual
> > > error.
> >
> >     Hm, I decided to check drivers/base/dd.c and I think I maybe know the
> > reason now: -ENXIO, usually returned by platform_get_irq(), is silently
> > "swallowed" by really_probe(); to be precise, -ENODEV and -ENXIO are only
> > reported with pr_debug(), while -ENOENT causes printk(KERN_WARNING, ...)...

> Sorry, I'm confused...  What should it be?  v1 or v2?  Here are the counts
> of the different constants returned on failure of platform_get_irq:

   I was somewhat confused myself but then I remembered about the deferred 
probing -- overriding error code basically just disables it in this case.

> ENODEV: 84
> ENXIO: 67

  Those 2 totally make no sense. :-)

> EINVAL: 61
> ENOENT: 29
> EBUSY: 11

   Hm...

> EIO: 2
> EPROBE_DEFER: 1

   Hm, and that last one is unconditional?

> julia

MBR, Sergei

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