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Commit f4a821ce authored by Zhang Rui's avatar Zhang Rui
Browse files

Thermal: Introduce locking for cdev.thermal_instances list. 



we need to go over all the thermal_instance list of a cooling device
to decide which cooling state to put the cooling device to.

But at this time, as a cooling device may be referenced in multiple
thermal zones, we need to lock the list first in case
another thermal zone is updating this cooling device.

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Reviewed-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: default avatarEduardo Valentin <eduardo.valentin@ti.com>
parent 908b9fb7

drivers/thermal/thermal_sys.c

+8 −0
Original line number Diff line number Diff line
@@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, 
		goto remove_symbol_link;



	mutex_lock(&tz->lock);

	mutex_lock(&cdev->lock);

	list_for_each_entry(pos, &tz->thermal_instances, tz_node)

	    if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {

		result = -EEXIST;
@@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, 
		list_add_tail(&dev->tz_node, &tz->thermal_instances);

		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);

	}

	mutex_unlock(&cdev->lock);

	mutex_unlock(&tz->lock);



	if (!result)
@@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, 
	struct thermal_instance *pos, *next;



	mutex_lock(&tz->lock);

	mutex_lock(&cdev->lock);

	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {

		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {

			list_del(&pos->tz_node);

			list_del(&pos->cdev_node);

			mutex_unlock(&cdev->lock);

			mutex_unlock(&tz->lock);

			goto unbind;

		}

	}

	mutex_unlock(&cdev->lock);

	mutex_unlock(&tz->lock);



	return -ENODEV;
@@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, 
	}



	strcpy(cdev->type, type);

	mutex_init(&cdev->lock);

	INIT_LIST_HEAD(&cdev->thermal_instances);

	cdev->ops = ops;

	cdev->updated = true;
@@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) 
	if (cdev->updated)

		return;



	mutex_lock(&cdev->lock);

	/* Make sure cdev enters the deepest cooling state */

	list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {

		if (instance->target == THERMAL_NO_TARGET)
@@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) 
		if (instance->target > target)

			target = instance->target;

	}

	mutex_unlock(&cdev->lock);

	cdev->ops->set_cur_state(cdev, target);

	cdev->updated = true;

}

include/linux/thermal.h

+1 −0
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ struct thermal_cooling_device { 
	void *devdata;

	const struct thermal_cooling_device_ops *ops;

	bool updated; /* true if the cooling device does not need update */

	struct mutex lock; /* protect thermal_instances list */

	struct list_head thermal_instances;

	struct list_head node;

};