Commit 423de5b5 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

thermal/of: Fix cdev lookup in thermal_of_should_bind() 

Since thermal_of_should_bind() terminates the loop after processing
the first child found in cooling-maps, it will never match more than
one cdev to a given trip point which is incorrect, as there may be
cooling-maps associating one trip point with multiple cooling devices.

Address this by letting the loop continue until either all
children have been processed or a matching one has been found.

To avoid adding conditionals or goto statements, put the loop in
question into a separate function and make that function return
right away after finding a matching cooling-maps entry.

Fixes: 94c6110b ("thermal/of: Use the .should_bind() thermal zone callback")
Link: https://lore.kernel.org/linux-pm/20250219-fix-thermal-of-v1-1-de36e7a590c4@chromium.org/


Reported-by: default avatarYu-Che Cheng <giver@chromium.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarYu-Che Cheng <giver@chromium.org>
Tested-by: default avatarYu-Che Cheng <giver@chromium.org>
Reviewed-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Tested-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/2788228.mvXUDI8C0e@rjwysocki.net
parent 4ecaa757

drivers/thermal/thermal_of.c

+29 −21
Original line number Diff line number Diff line
@@ -274,25 +274,11 @@ static bool thermal_of_get_cooling_spec(struct device_node *map_np, int index, 
	return true;

}



static bool thermal_of_should_bind(struct thermal_zone_device *tz,

static bool thermal_of_cm_lookup(struct device_node *cm_np,

				 const struct thermal_trip *trip,

				 struct thermal_cooling_device *cdev,

				 struct cooling_spec *c)

{

	struct device_node *tz_np, *cm_np;

	bool result = false;



	tz_np = thermal_of_zone_get_by_name(tz);

	if (IS_ERR(tz_np)) {

		pr_err("Failed to get node tz by name\n");

		return false;

	}



	cm_np = of_get_child_by_name(tz_np, "cooling-maps");

	if (!cm_np)

		goto out;



	/* Look up the trip and the cdev in the cooling maps. */

	for_each_child_of_node_scoped(cm_np, child) {

		struct device_node *tr_np;

		int count, i;
@@ -302,19 +288,41 @@ static bool thermal_of_should_bind(struct thermal_zone_device *tz, 
			continue;



		/* The trip has been found, look up the cdev. */

		count = of_count_phandle_with_args(child, "cooling-device", "#cooling-cells");

		count = of_count_phandle_with_args(child, "cooling-device",

						   "#cooling-cells");

		if (count <= 0)

			pr_err("Add a cooling_device property with at least one device\n");



		for (i = 0; i < count; i++) {

			result = thermal_of_get_cooling_spec(child, i, cdev, c);

			if (result)

				break;

			if (thermal_of_get_cooling_spec(child, i, cdev, c))

				return true;

		}

	}



	return false;

}



		break;

static bool thermal_of_should_bind(struct thermal_zone_device *tz,

				   const struct thermal_trip *trip,

				   struct thermal_cooling_device *cdev,

				   struct cooling_spec *c)

{

	struct device_node *tz_np, *cm_np;

	bool result = false;



	tz_np = thermal_of_zone_get_by_name(tz);

	if (IS_ERR(tz_np)) {

		pr_err("Failed to get node tz by name\n");

		return false;

	}



	cm_np = of_get_child_by_name(tz_np, "cooling-maps");

	if (!cm_np)

		goto out;



	/* Look up the trip and the cdev in the cooling maps. */

	result = thermal_of_cm_lookup(cm_np, trip, cdev, c);



	of_node_put(cm_np);

out:

	of_node_put(tz_np);