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SubjectRE: [PATCH] regulator: core: fix error path for regulator_set_voltage_unlocked
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Hi Dmitry,

Thanks,

On 18 March 2019 16:03, Dmitry Osipenko wrote:

> Subject: Re: [PATCH] regulator: core: fix error path for
> regulator_set_voltage_unlocked
>
> 18.03.2019 18:32, Steve Twiss пишет:
> > During several error paths in the function
> > regulator_set_voltage_unlocked() the value of 'ret' can take on negative
> > error values. However, in calls that go through the 'goto out' statement,
> > this return value is lost and return 0 is used instead, indicating a
> > 'pass'.
> >
> > There are several cases where this function should legitimately return a
> > fail instead of a pass: one such case includes constraints check during
> > voltage selection in the call to regulator_check_voltage(), which can
> > have -EINVAL for the case when an unsupported voltage is incorrectly
> > requested. In that case, -22 is expected as the return value, not 0.
> >
> > Fixes: 9243a195be7a ("regulator: core: Change voltage setting path")
> > Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
> > ---
> > drivers/regulator/core.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> > index 68473d0..caf8743 100644
> > --- a/drivers/regulator/core.c
> > +++ b/drivers/regulator/core.c
> > @@ -3326,7 +3326,7 @@ static int regulator_set_voltage_unlocked(struct
> regulator *regulator,
> > goto out2;
> >
> > out:
> > - return 0;
> > + return ret;
> > out2:
> > voltage->min_uV = old_min_uV;
> > voltage->max_uV = old_max_uV;
> >
>
> Looks like a good catch.
>
> Probably will be a bit better to write this as:
>
> /* for not coupled regulators this will just set the voltage */
> ret = regulator_balance_voltage(rdev, state);
> - if (ret < 0)
> - goto out2;
> -
> + if (ret < 0) {
> + voltage->min_uV = old_min_uV;
> + voltage->max_uV = old_max_uV;
> + }
> out:
> - return 0;
> -out2:
> - voltage->min_uV = old_min_uV;
> - voltage->max_uV = old_max_uV;
> -
> return ret;
> }

I've just had a very similar conversation with Adam Thomson who sits near me and also
said the two gotos make it look confusing.

Honestly -- I wasn't convinced because it looked obvious to me, but you are the second
person to say it ..
CC: Adam Thomson

So, ok. Agreed. :)
I'll make the change and resend.

Regards,
Steve
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