Re: [PATCH] thermal: step_wise: set throttle target within thermalinstance limits

[Eduardo Valentin]

On 09-04-2013 13:09, Andrew Bresticker wrote:
> Hi Eduardo,
>
> On Tue, Apr 9, 2013 at 8:00 AM, Eduardo Valentin
> <eduardo.valentin@xxxxxx> wrote:
> > Hi Andrew,
> >
> >
> > On 08-04-2013 19:56, Andrew Bresticker wrote:
> > > When selecting a target cooling state in get_target_state(), make sure
> > > that the state is at least as high as the minimum when the temperature
> > > is rising and at least as low as the maximum when the temperature is
> > > falling.  Previously the cooling level would only be incremented or
> > > decremented by one in these cases.
> > >
> > > Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> > > ---
> > >    drivers/thermal/step_wise.c | 4 ++++
> > >    1 file changed, 4 insertions(+)
> > >
> > > diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c
> > > index 0cd5e9f..49992a4 100644
> > > --- a/drivers/thermal/step_wise.c
> > > +++ b/drivers/thermal/step_wise.c
> > > @@ -47,9 +47,13 @@ static unsigned long get_target_state(struct
> > > thermal_instance *instance,
> > >          if (trend == THERMAL_TREND_RAISING) {
> > >                  cur_state = cur_state < instance->upper ?
> > >                              (cur_state + 1) : instance->upper;
> > > +               if (cur_state < instance->lower)
> > > +                       cur_state = instance->lower;
> > >          } else if (trend == THERMAL_TREND_DROPPING) {
> > >                  cur_state = cur_state > instance->lower ?
> > >                              (cur_state - 1) : instance->lower;
> > > +               if (cur_state > instance->upper)
> > > +                       cur_state = instance->upper;
> > >          }
> >
> >
> >
> > In which situations cur_state will be out of the [lower;upper] boundaries? I
> > mean at this point while temperature is rising, and we are rising the
> > cooling level, we should be already above lower (and vice-versa). Can you
> > please describe better the situation you are trying to cover/ that you have
> > identified?
>
> Suppose we hit a trip point which has bounds from 5 to 10, but
> cur_state is 0 because there has previously been no thermal
> throttling.  In that case, we would only go to level 1, even though
> the thermal instance specifies we should be between 5 and 10.  This
> patch would fix it so that we go directly to level 5 instead.
>
> I will resend this with a more descriptive commit message.

Thanks, I appreciate it.

> > >          return cur_state;
>
> Thanks,
> Andrew

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