Re: [patch] da9052-battery: don't free IRQ that wasn't requested

From: Dan Carpenter
Date: Thu Sep 06 2012 - 11:08:17 EST


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@xxxxxxxxxx>
> >
> > 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/