Re: [PATCH] regulator: core: fix error path of regulator_ena_gpio_free

[Krzysztof Adamski]

On Tue, Feb 23, 2016 at 03:18:59PM +0000, Jon Hunter wrote:
> On 23/02/16 14:47, Krzysztof Adamski wrote:
> > Signed-off-by: Krzysztof Adamski <krzysztof.adamski@xxxxxxxxx>
> > Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx>
>
> Nit ... I think that order of the above should be reversed.

Couldn't find any reference stating proper order of those tags and 
briefly looking at other commit messages shows this order as quite 
common.

> > ---
> >  drivers/regulator/core.c | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> > index 6ee9ba4..d1e7859 100644
> > --- a/drivers/regulator/core.c
> > +++ b/drivers/regulator/core.c
> > @@ -3919,7 +3919,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
> >  		if (ret != 0) {
> >  			rdev_err(rdev, "Failed to request enable GPIO%d: %d\n",
> >  				 config->ena_gpio, ret);
> > -			goto wash;
> > +			goto clean;
> >  		}
> >  	}
> >
> > @@ -3942,7 +3942,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
> >
> >  	ret = set_machine_constraints(rdev, constraints);
> >  	if (ret < 0)
> > -		goto scrub;
> > +		goto wash;
> >
> >  	if (init_data && init_data->supply_regulator)
> >  		rdev->supply_name = init_data->supply_regulator;
> > @@ -3972,10 +3972,8 @@ out:
> >  unset_supplies:
> >  	unset_regulator_supplies(rdev);
> >
> > -scrub:
> > -	regulator_ena_gpio_free(rdev);
> > -
> >  wash:
> > +	regulator_ena_gpio_free(rdev);
> >  	device_unregister(&rdev->dev);
> >  	/* device core frees rdev */
> >  	rdev = ERR_PTR(ret);
>
> What about the case where device_register() fails? I think you still
> call clean and so you will leak the gpio?
>
> Jon
True. I couldn't find anything more clever than calling 
regulator_ena_gpio_free() in two paths like in an upcomming v2. Putting 
it inside of regulator_dev_release() won't entirely fix the problem 
either as this won't be called in this particular case 
(device_register() fail). I personally still prefer calling 
regulator_ena_gpio_free() inside of regulator_register insted of 
deffering it to regulator_dev_release() as it seems to be clearer to me.

Best regards,
Krzysztof Adamski