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From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: Ashish Jangam <ashish.jangam@kpitcummins.com>,
	Anton Vorontsov <cbou@mail.ru>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] da9052-battery: don't free IRQ that wasn't requested
Date: Thu, 06 Sep 2012 15:07:58 +0000	[thread overview]
Message-ID: <20120906150758.GL19410@mwanda> (raw)
In-Reply-To: <50475D75.2040908@bfs.de>

On Wed, Sep 05, 2012 at 04:11:01PM +0200, walter harms wrote:
> 
> 
> Am 05.09.2012 14:34, schrieb Dan Carpenter:
> > We should decrement "i" before doing the free_irq().  If we call this
> > because request_threaded_irq() failed then we don't want to free the
> > thing which failed.  Or in the case where we get here because
> > power_supply_register() failed then the original codes does a read past
> > the end of the array.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/drivers/power/da9052-battery.c b/drivers/power/da9052-battery.c
> > index 20b86ed..d9d034d 100644
> > --- a/drivers/power/da9052-battery.c
> > +++ b/drivers/power/da9052-battery.c
> > @@ -623,7 +623,7 @@ static s32 __devinit da9052_bat_probe(struct platform_device *pdev)
> >  	return 0;
> >  
> >  err:
> > -	for (; i >= 0; i--) {
> > +	while (--i >= 0) {
> >  		irq = platform_get_irq_byname(pdev, da9052_bat_irqs[i]);
> >  		free_irq(bat->da9052->irq_base + irq, bat);
> >  	}
> 
> hi da,
> (my usual nitpicking ...)

Ha ha.  Your nit picks are welcome even if I don't always agree.

> since a lot of people do make mistakes on count-down-loops, is there any chance to
> make this a common count-up-for()-loop ?
> like:

I like the count down loops...  It feels very natural to unwind that
way.

>    for (j=0; j <= i ;j++ ) {
               ^^^^^^
The count up loops are prone to the exact same off by one bugs.  ;)
You've got one in your sample code.  Plus I'd have to declare
another variable and send a v2 patch and I am very lazy...  So in
this case I think should just take my original patch.

regards,
dan carpenter


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: Ashish Jangam <ashish.jangam@kpitcummins.com>,
	Anton Vorontsov <cbou@mail.ru>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] da9052-battery: don't free IRQ that wasn't requested
Date: Thu, 6 Sep 2012 08:07:58 -0700	[thread overview]
Message-ID: <20120906150758.GL19410@mwanda> (raw)
In-Reply-To: <50475D75.2040908@bfs.de>

On Wed, Sep 05, 2012 at 04:11:01PM +0200, walter harms wrote:
> 
> 
> Am 05.09.2012 14:34, schrieb Dan Carpenter:
> > We should decrement "i" before doing the free_irq().  If we call this
> > because request_threaded_irq() failed then we don't want to free the
> > thing which failed.  Or in the case where we get here because
> > power_supply_register() failed then the original codes does a read past
> > the end of the array.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/drivers/power/da9052-battery.c b/drivers/power/da9052-battery.c
> > index 20b86ed..d9d034d 100644
> > --- a/drivers/power/da9052-battery.c
> > +++ b/drivers/power/da9052-battery.c
> > @@ -623,7 +623,7 @@ static s32 __devinit da9052_bat_probe(struct platform_device *pdev)
> >  	return 0;
> >  
> >  err:
> > -	for (; i >= 0; i--) {
> > +	while (--i >= 0) {
> >  		irq = platform_get_irq_byname(pdev, da9052_bat_irqs[i]);
> >  		free_irq(bat->da9052->irq_base + irq, bat);
> >  	}
> 
> hi da,
> (my usual nitpicking ...)

Ha ha.  Your nit picks are welcome even if I don't always agree.

> since a lot of people do make mistakes on count-down-loops, is there any chance to
> make this a common count-up-for()-loop ?
> like:

I like the count down loops...  It feels very natural to unwind that
way.

>    for (j=0; j <= i ;j++ ) {
               ^^^^^^
The count up loops are prone to the exact same off by one bugs.  ;)
You've got one in your sample code.  Plus I'd have to declare
another variable and send a v2 patch and I am very lazy...  So in
this case I think should just take my original patch.

regards,
dan carpenter


  reply	other threads:[~2012-09-06 15:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-05 12:34 [patch] da9052-battery: don't free IRQ that wasn't requested Dan Carpenter
2012-09-05 12:34 ` Dan Carpenter
2012-09-05 14:11 ` walter harms
2012-09-05 14:11   ` walter harms
2012-09-06 15:07   ` Dan Carpenter [this message]
2012-09-06 15:07     ` Dan Carpenter
2012-09-20 22:02     ` Anton Vorontsov
2012-09-20 22:02       ` Anton Vorontsov

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