linux-kernel - Re: [PATCH v4 04/10] thermal: core: Add thermal_zone_update_trip

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Date:   Mon, 7 Aug 2023 13:29:46 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Michal Wilczynski <michal.wilczynski@...el.com>,
        Zhang Rui <rui.zhang@...el.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: Re: [PATCH v4 04/10] thermal: core: Add
 thermal_zone_update_trip_temp() helper routine

On 04/08/2023 23:05, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Introduce a helper routine called thermal_zone_update_trip_temp() that
> can be used to update a trip point's temperature with the help of a
> pointer to local data associated with that trip point provided by
> the thermal driver that created it.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
> 
> New patch in v4.
> 
> ---
>   drivers/thermal/thermal_trip.c |   37 +++++++++++++++++++++++++++++++++++++
>   include/linux/thermal.h        |    4 ++++
>   2 files changed, 41 insertions(+)
> 
> Index: linux-pm/drivers/thermal/thermal_trip.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_trip.c
> +++ linux-pm/drivers/thermal/thermal_trip.c
> @@ -180,3 +180,40 @@ int thermal_zone_set_trip(struct thermal
>   
>   	return 0;
>   }
> +
> +/**
> + * thermal_zone_update_trip_temp - Update the trip point temperature.
> + * @tz: Thermal zone.
> + * @trip_priv: Trip tag.
> + * @temp: New trip temperature.
> + *
> + * This only works for thermal zones using trip tables and its caller must
> + * ensure that the zone lock is held before using it.
> + *
> + * @trip_priv is expected to be the value that has been stored by the driver
> + * in the struct thermal_trip representing the trip point in question, so it
> + * can be matched against the value of the priv field in that structure.
> + *
> + * If @trip_priv does not match any trip point in the trip table of @tz,
> + * nothing happens.
> + */
> +void thermal_zone_update_trip_temp(struct thermal_zone_device *tz,
> +				   void *trip_priv, int temperature)
> +{
> +	int i;
> +
> +	lockdep_assert_held(&tz->lock);
> +
> +	if (!tz->trips || !trip_priv)
> +		return;
> +
> +	for (i = 0; i < tz->num_trips; i++) {
> +		struct thermal_trip *trip = &tz->trips[i];
> +
> +		if (trip->priv == trip_priv) {
> +			trip->temperature = temperature;
> +			return;
> +		}
> +	}
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_update_trip_temp);

This function would imply the comparator is always trip->priv but if we 
want another comparison eg. trip->priv->id, that won't be possible.

Actually, I think you can reuse an existing function with a simple 
change, for_each_thermal_trip() located in thermal_core.h.

The changes would be renaming it without the '__' prefix and moving it 
in include/linux/thermal.h.

Then the comparison function and the temperature change can be an ACPI 
driver specific callback passed as parameter to for_each_thermal_zone



> Index: linux-pm/include/linux/thermal.h
> ===================================================================
> --- linux-pm.orig/include/linux/thermal.h
> +++ linux-pm/include/linux/thermal.h
> @@ -286,9 +286,13 @@ int __thermal_zone_get_trip(struct therm
>   			    struct thermal_trip *trip);
>   int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
>   			  struct thermal_trip *trip);
> +void thermal_zone_update_trip_temp(struct thermal_zone_device *tz,
> +				   void *trip_priv, int temperature);
>   
>   int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
>   			  const struct thermal_trip *trip);
> +void thermal_zone_update_trip_temp(struct thermal_zone_device *tz,
> +				   void *trip_priv, int temperature);
>   
>   int thermal_zone_get_num_trips(struct thermal_zone_device *tz);
>   
> 
> 
> 

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