Re: [Patch v5 1/2] ACPI: thermal: Add Thermal fast Sampling Period (_TFP) support

[Sumit Gupta <sumitg@xxxxxxxxxx>]

On 18/10/23 17:18, Rafael J. Wysocki wrote:
> External email: Use caution opening links or attachments
>
>
> On Sat, Oct 14, 2023 at 12:54 PM Sumit Gupta <sumitg@xxxxxxxxxx> wrote:
> > From: Jeff Brasen <jbrasen@xxxxxxxxxx>
> >
> > Add support of "Thermal fast Sampling Period (_TFP)" for Passive cooling.
> > As per [1], _TFP overrides the "Thermal Sampling Period (_TSP)" if both
> > are present in a Thermal zone.
> >
> > [1] ACPI Specification 6.4 - section 11.4.17. _TFP (Thermal fast Sampling
> >      Period)"
> >
> > Signed-off-by: Jeff Brasen <jbrasen@xxxxxxxxxx>
> > Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
> > ---
> >   drivers/acpi/thermal.c | 17 +++++++++++------
> >   1 file changed, 11 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
> > index d98ff69303b3..a91e3d566858 100644
> > --- a/drivers/acpi/thermal.c
> > +++ b/drivers/acpi/thermal.c
> > @@ -90,7 +90,7 @@ struct acpi_thermal_passive {
> >          struct acpi_thermal_trip trip;
> >          unsigned long tc1;
> >          unsigned long tc2;
> > -       unsigned long tsp;
> > +       unsigned long passive_delay;
>
> This is a passive trip structure anyway, so the "passive_" prefix is
> redundant here.  "delay" alone would be fine.
will change in v6.

> >   };
> >
> >   struct acpi_thermal_active {
> > @@ -404,11 +404,16 @@ static bool passive_trip_params_init(struct acpi_thermal *tz)
> >
> >          tz->trips.passive.tc2 = tmp;
> >
> > -       status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
> > -       if (ACPI_FAILURE(status))
> > -               return false;
> > +       status = acpi_evaluate_integer(tz->device->handle, "_TFP", NULL, &tmp);
> > +       if (ACPI_FAILURE(status)) {
> > +               status = acpi_evaluate_integer(tz->device->handle, "_TSP", NULL, &tmp);
> > +               if (ACPI_FAILURE(status))
> > +                       return false;
> >
> > -       tz->trips.passive.tsp = tmp;
> > +               tz->trips.passive.passive_delay = tmp * 100;
> > +       } else {
> > +               tz->trips.passive.passive_delay = tmp;
> > +       }
>
> I would prefer the if () statement above to be structured the other
> way around, that is
>
>   status = ...
>   if (ACPI_SUCCESS(status)) {
>          tz->trips.passive.delay = tmp;
>          return true;
> }
>
> status = ...
> if (ACPI_FAILURE(status))
>           return false;
>
> etc.

Ok. will change in v6.

> >          return true;
> >   }
> > @@ -904,7 +909,7 @@ static int acpi_thermal_add(struct acpi_device *device)
> >
> >          acpi_trip = &tz->trips.passive.trip;
> >          if (acpi_thermal_trip_valid(acpi_trip)) {
> > -               passive_delay = tz->trips.passive.tsp * 100;
> > +               passive_delay = tz->trips.passive.passive_delay;
> >
> >                  trip->type = THERMAL_TRIP_PASSIVE;
> >                  trip->temperature = acpi_thermal_temp(tz, acpi_trip->temp_dk);
> > --
> > 2.17.1