linux-kernel - Re: [PATCH 03/10] net: ezchip: nps_enet: Fix platform_get

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Message-ID: <20171204164224.GU10595@n2100.armlinux.org.uk>
Date:   Mon, 4 Dec 2017 16:42:25 +0000
From:   Russell King - ARM Linux <linux@...linux.org.uk>
To:     David Miller <davem@...emloft.net>
Cc:     arvind.yadav.cs@...il.com, f.fainelli@...il.com,
        netdev@...r.kernel.org, michal.simek@...inx.com,
        linux-kernel@...r.kernel.org, opendmb@...il.com,
        mkl@...gutronix.de, linux-arm-kernel@...ts.infradead.org,
        Vladislav.Zakharov@...opsys.com, wg@...ndegger.com
Subject: Re: [PATCH 03/10] net: ezchip: nps_enet: Fix platform_get_irq's
 error checking

On Mon, Dec 04, 2017 at 11:34:48AM -0500, David Miller wrote:
> From: Russell King - ARM Linux <linux@...linux.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@...il.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@...il.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.

Indeed, the commit message is wrong, and that's already been pointed out
in previous patch sets.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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