Re: [PATCH] regulator: core: if voltage scaling fails, restoreoriginal voltage values

From: Felipe Balbi
Date: Wed Dec 12 2012 - 14:07:19 EST


Hi,

On Wed, Dec 12, 2012 at 12:13:35PM -0600, Robert Nelson wrote:
> On Wed, Dec 12, 2012 at 5:45 AM, Paolo Pisati
> <paolo.pisati@xxxxxxxxxxxxx> wrote:
> > Signed-off-by: Paolo Pisati <paolo.pisati@xxxxxxxxxxxxx>
> > ---
> > drivers/regulator/core.c | 16 ++++++++++++++--
> > 1 file changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> > index e872c8b..c347fd0 100644
> > --- a/drivers/regulator/core.c
> > +++ b/drivers/regulator/core.c
> > @@ -2250,6 +2250,7 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
> > {
> > struct regulator_dev *rdev = regulator->rdev;
> > int ret = 0;
> > + int old_min_uV, old_max_uV;
> >
> > mutex_lock(&rdev->mutex);
> >
> > @@ -2271,18 +2272,29 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
> > ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
> > if (ret < 0)
> > goto out;
> > +
> > + /* restore original values in case of error */
> > + old_min_uV = regulator->min_uV;
> > + old_max_uV = regulator->max_uV;
> > regulator->min_uV = min_uV;
> > regulator->max_uV = max_uV;
> >
> > ret = regulator_check_consumers(rdev, &min_uV, &max_uV);
> > if (ret < 0)
> > - goto out;
> > + goto out2;
> >
> > ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
> > -
> > + if (ret < 0)
> > + goto out2;
> > +
> > out:
> > mutex_unlock(&rdev->mutex);
> > return ret;
> > +out2:
> > + regulator->min_uV = old_min_uV;
> > + regulator->max_uV = old_max_uV;
> > + mutex_unlock(&rdev->mutex);
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(regulator_set_voltage);
> >
> > --
> > 1.7.10.4
>
> Nice! This fixes the 800Mhz lockup on bootup after a software reset we
> were seeing on the Beagle xM's with v3.7.x/v3.6.x...
>
> Tested-by: Robert Nelson <robertcnelson@xxxxxxxxx>

if this fixes a boot lockup with older kernel, I believe this deserves a
Cc: stable@xxxxxxxxxxxxxxxx

--
balbi

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