Re: [PATCH 03/10] net: ezchip: nps_enet: Fix platform_get_irq's error checking

[Russell King - ARM Linux]

On Mon, Dec 04, 2017 at 11:20:49AM -0500, David Miller wrote:
> From: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
> 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@xxxxxxxxx>
> > ---
> >  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.

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