Re: [PATCH 1/3] thermal/drivers/intel: Use generic trip points for quark_dts

[Daniel Lezcano]

On 26/01/2023 15:15, Rafael J. Wysocki wrote:
> On Wed, Jan 18, 2023 at 7:16 PM Daniel Lezcano
> <daniel.lezcano@xxxxxxxxxx> wrote:
> > The thermal framework gives the possibility to register the trip
> > points with the thermal zone. When that is done, no get_trip_* ops are
> > needed and they can be removed.
> >
> > Convert ops content logic into generic trip points and register them with the
> > thermal zone.
> >
> > Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> > ---

[ ... ]

> > -       aux_entry->tzone = thermal_zone_device_register("quark_dts",
> > -                       QRK_MAX_DTS_TRIPS,
> > -                       wr_mask,
> > -                       aux_entry, &tzone_ops, NULL, 0, polling_delay);
> > +       err = get_trip_temp(QRK_DTS_ID_TP_CRITICAL, &temperature);
> > +       if (err)
> > +               goto err_ret;
> > +
> > +       aux_entry->trips[QRK_DTS_ID_TP_CRITICAL].temperature = temperature;
> > +       aux_entry->trips[QRK_DTS_ID_TP_CRITICAL].type = THERMAL_TRIP_CRITICAL;
> > +
> > +       err = get_trip_temp(QRK_DTS_ID_TP_HOT, &temperature);
> > +       if (err)
> > +               goto err_ret;
>
> If I'm not mistaken, this won't even try to register the thermal zone
> if at least one trip cannot be initialized, but previously it was
> registered in that case, but the trips that failed to respond were
> disabled.
>
> This is a change in behavior that would at least need to be documented
> in the changelog, but it isn't.
>
> I'm not sure if it is safe to make even, however.

Thanks for catching this.

Two solutions:

1. Set the temperature to THERMAL_TEMP_INVALID and change 
get_thermal_trip() to return -EINVAL or -ERANGE if the temperature is 
THERMAL_TEMP_INVALID

2. Register only the valid trip points.

What would be the preferable way ?


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