Re: [PATCH 4/7 v2] net: ethernet: i825xx: Fix platform_get_irq's error checking

[Sergei Shtylyov]

On 12/4/2017 9:25 PM, David Miller wrote:

> > @@ -120,9 +120,10 @@ static int sni_82596_probe(struct platform_device *dev)
> >   	netdevice->dev_addr[5] = readb(eth_addr + 0x06);
> >   	iounmap(eth_addr);
> >   
> > -	if (!netdevice->irq) {
> > +	if (netdevice->irq <= 0) {
> >   		printk(KERN_ERR "%s: IRQ not found for i82596 at 0x%lx\n",
> >   			__FILE__, netdevice->base_addr);
> > +		retval = netdevice->irq ? netdevice->irq : -ENODEV;
> >   		goto probe_failed;
> >   	}
>
> Ok, thinking about this some more...
>
> It is impossible to use platform_get_irq() without every single call
> site having this funny:
>
> 	ret = val ? val : -ENODEV;
>
> sequence.
>
> This is unnecessary duplication and it is also error prone, so I
> really think this logic belongs in platform_get_irq() itself.  It can
> convert '0' to -ENODEV and that way we need no special logic in the
> callers at all.

   Well, we can have:

	return r && r->start ? r->start : -ENXIO;

instead of:

	return r ? r->start : -ENXIO;

at the end of platform_get_irq(). But I don't really think it's worth doing -- 
request_irq() doesn't filter out IRQ0 anyway, IIRC...

MBR, Sergei