Re: [PATCH v3 3/8] thermal: core: Add routines for locking and unlocking thermal zones

[Daniel Lezcano]

Hi Rafael,


On 25/07/2023 14:08, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> Add thermal_zone_device_lock() and thermal_zone_device_unlock() for
> acquiring and releasing the thermal zone lock, respectively.
>
> They will be used by the ACPI thermal driver to protect trip point
> temperature updates against races with accesses from elsewhere.

This change goes to the opposite direction of the previous thermal zone 
cleanup and encapsulation we have done recently.

Here we give the possibility to a driver to act on the thermal core 
internals.

Ideally, we should see tz->lock only in thermal_core.c


> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
>
> v2 -> v3: No changes.
>
> v1 -> v2: New patch.
>
> ---
>   drivers/thermal/thermal_core.c |   13 +++++++++++++
>   include/linux/thermal.h        |    2 ++
>   2 files changed, 15 insertions(+)
>
> Index: linux-pm/drivers/thermal/thermal_core.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.c
> +++ linux-pm/drivers/thermal/thermal_core.c
> @@ -497,6 +498,18 @@ void thermal_zone_device_update(struct t
>   }
>   EXPORT_SYMBOL_GPL(thermal_zone_device_update);
>   
> +void thermal_zone_device_lock(struct thermal_zone_device *tz)
> +{
> +	mutex_lock(&tz->lock);
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_device_lock);
> +
> +void thermal_zone_device_unlock(struct thermal_zone_device *tz)
> +{
> +	mutex_unlock(&tz->lock);
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_device_unlock);
> +
>   static void thermal_zone_device_check(struct work_struct *work)
>   {
>   	struct thermal_zone_device *tz = container_of(work, struct
> Index: linux-pm/include/linux/thermal.h
> ===================================================================
> --- linux-pm.orig/include/linux/thermal.h
> +++ linux-pm/include/linux/thermal.h
> @@ -336,6 +336,8 @@ int thermal_zone_unbind_cooling_device(s
>   				       struct thermal_cooling_device *);
>   void thermal_zone_device_update(struct thermal_zone_device *,
>   				enum thermal_notify_event);
> +void thermal_zone_device_lock(struct thermal_zone_device *tz);
> +void thermal_zone_device_unlock(struct thermal_zone_device *tz);
>   
>   struct thermal_cooling_device *thermal_cooling_device_register(const char *,
>   		void *, const struct thermal_cooling_device_ops *);

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