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

From: Julia Lawall
Date: Sat Dec 26 2015 - 15:08:21 EST


On Sat, 26 Dec 2015, Sergei Shtylyov wrote:

> Hello.
>
> On 12/26/2015 08:50 PM, Sergei Shtylyov 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:

ENODEV: 84
ENXIO: 67
EINVAL: 61
ENOENT: 29
EBUSY: 11
EIO: 2
EPROBE_DEFER: 1

julia
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