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Date: Mon, 04 Dec 2017 11:34:48 -0500 (EST)
Message-Id: <20171204.113448.651799079717687661.davem@davemloft.net>
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Subject: Re: [PATCH 03/10] net: ezchip: nps_enet: Fix platform_get_irq's
 error checking
From: David Miller <davem@davemloft.net>
In-Reply-To: <20171204162447.GT10595@n2100.armlinux.org.uk>
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From: Russell King - ARM Linux <linux@armlinux.org.uk>
Date: Mon, 4 Dec 2017 16:24:47 +0000

> On Mon, Dec 04, 2017 at 11:20:49AM -0500, David Miller wrote:
>> From: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> Date: Sun,  3 Dec 2017 00:56:15 +0530
>> 
>> > The platform_get_irq() function returns negative if an error occurs.
>> > zero or positive number on success. platform_get_irq() error checking
>> > for zero is not correct. And remove unnecessary check for free_netdev().
>> > 
>> > Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> > ---
>> >  drivers/net/ethernet/ezchip/nps_enet.c | 7 +++----
>> >  1 file changed, 3 insertions(+), 4 deletions(-)
>> > 
>> > diff --git a/drivers/net/ethernet/ezchip/nps_enet.c b/drivers/net/ethernet/ezchip/nps_enet.c
>> > index 659f1ad..82dc6d0 100644
>> > --- a/drivers/net/ethernet/ezchip/nps_enet.c
>> > +++ b/drivers/net/ethernet/ezchip/nps_enet.c
>> > @@ -623,9 +623,9 @@ static s32 nps_enet_probe(struct platform_device *pdev)
>> >  
>> >  	/* Get IRQ number */
>> >  	priv->irq = platform_get_irq(pdev, 0);
>> > -	if (!priv->irq) {
>> > +	if (priv->irq <= 0) {
>> >  		dev_err(dev, "failed to retrieve <irq Rx-Tx> value from device tree\n");
>> > -		err = -ENODEV;
>> > +		err = priv->irq ? priv->irq : -ENODEV;
>> 
>> If platform_get_irq() returns "zero or positive number on success" then this
>> test is wrong and should be "if (priv->irq < 0)"
>> 
>> Also, this series is a mix of different kinds of changes.
>> 
>> Please separate out the platform IRQ error checking and just submit exactly
>> those changes as a patch series.
>> 
>> The other bug fixes should be submitted outside of those changes since they
>> are unrelated.
> 
> The issue of whether IRQ 0 is valid or not has been covered several times
> by Linus, and the result is that it is deemed by Linus that IRQ 0 is not
> a valid interrupt.

Then either platform_get_irq() as defined or this commit message (or both)
are wrong.