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

From: David Miller
Date: Tue Dec 05 2017 - 10:50:00 EST


From: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
Date: Tue, 5 Dec 2017 11:04:55 +0530

> Hi David,
>
>
> On Monday 04 December 2017 11:55 PM, David Miller wrote:
>> From: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
>> Date: Mon, 4 Dec 2017 23:18:20 +0530
>>
>>> @@ -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.
> platform_get_irq() will return 0 only for sparc, If sparc initialize
> platform
> data irq[PROMINTR_MAX] as zero. Otherwise platform_get_irq() will
> never return
> 0. It will return either IRQ number or error (as negative number). But
> I am getting
> review comment by reviewer/maintainer in other subsystem to add check
> for
> zero. So I have done same changes here. Please correct me if i am
> wrong.

If you make the change that I suggest, you instead can check for
'-ENODEV' to mean no IRQ.