Date: Mon, 04 Dec 2017 13:25:56 -0500 (EST)
Message-Id: <20171204.132556.1601454745789376393.davem@davemloft.net>
To: arvind.yadav.cs@gmail.com
Cc: wg@grandegger.com, mkl@pengutronix.de, michal.simek@xilinx.com,
        opendmb@gmail.com, f.fainelli@gmail.com, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org
Subject: Re: [PATCH 4/7 v2] net: ethernet: i825xx: Fix platform_get_irq's
 error checking
From: David Miller <davem@davemloft.net>
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From: Arvind Yadav <arvind.yadav.cs@gmail.com>
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.