linux-kernel - Re: [PATCH 3/3] thermal/drivers/intel: Use generic trip points for intel_soc_dts

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Message-ID: <ff598dd3-91d0-b660-7821-e34177056954@linaro.org>
Date:   Mon, 23 Jan 2023 19:09:46 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
Cc:     srinivas.pandruvada@...ux.intel.com, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, rui.zhang@...el.com,
        Daniel Lezcano <daniel.lezcano@...nel.org>,
        Amit Kucheria <amitk@...nel.org>
Subject: Re: [PATCH 3/3] thermal/drivers/intel: Use generic trip points for
 intel_soc_dts_iosf


Hi Srinivas,

On 19/01/2023 21:04, Rafael J. Wysocki wrote:
> On Wed, Jan 18, 2023 at 7:16 PM Daniel Lezcano
> <daniel.lezcano@...aro.org> wrote:
>>
>> From: Daniel Lezcano <daniel.lezcano@...nel.org>
>>
>> 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@...aro.org>
>> ---

[ ... ]

>>
>> @@ -320,7 +304,8 @@ static int add_dts_thermal_zone(int id, struct intel_soc_dts_sensor_entry *dts,
>>          dts->trip_mask = trip_mask;
>>          dts->trip_count = trip_count;
>>          snprintf(name, sizeof(name), "soc_dts%d", id);
>> -       dts->tzone = thermal_zone_device_register(name,
>> +       dts->tzone = thermal_zone_device_register_with_trips(name,
>> +                                                 dts->trips,
>>                                                    trip_count,
>>                                                    trip_mask,
>>                                                    dts, &tzone_ops,
>> @@ -430,27 +415,28 @@ struct intel_soc_dts_sensors *intel_soc_dts_iosf_init(
>>                  notification = false;
>>          else
>>                  notification = true;
>> -       for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
>> -               sensors->soc_dts[i].sensors = sensors;
>> -               ret = add_dts_thermal_zone(i, &sensors->soc_dts[i],
>> -                                          notification, trip_count,
>> -                                          read_only_trip_count);
>> -               if (ret)
>> -                       goto err_free;
>> -       }
> 
> How is this change related to the rest of the patch?

We want to register the thermal zone with the trip points.

thermal_zone_device_register() becomes

thermal_zone_device_register_with_trips()

But in the current code, the trip points are updated after the thermal 
zones are created (and strictly speaking it is wrong as get_trip_temp 
can be invoked before the trip points are updated).

So the change inverts the initialization where we update the trip points 
and then we register the thermal zones.

>>
>>          for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
>>                  ret = update_trip_temp(&sensors->soc_dts[i], 0, 0,
>>                                         THERMAL_TRIP_PASSIVE);
>>                  if (ret)
>> -                       goto err_remove_zone;
>> +                       goto err_free;
>>
>>                  ret = update_trip_temp(&sensors->soc_dts[i], 1, 0,
>>                                         THERMAL_TRIP_PASSIVE);
>>                  if (ret)
>> -                       goto err_remove_zone;
>> +                       goto err_free;
>>          }
>>
>> +       for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
>> +               sensors->soc_dts[i].sensors = sensors;
>> +               ret = add_dts_thermal_zone(i, &sensors->soc_dts[i],
>> +                                          notification, trip_count,
>> +                                          read_only_trip_count);
>> +               if (ret)
>> +                       goto err_remove_zone;
>> +       }
>> +

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