linux-kernel - [RFC PATCH for 6.13 v1 13/20] thermal: core: Call thermal_governor_update

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Message-ID: <1921484.CQOukoFCf9@rjwysocki.net>
Date: Sat, 14 Sep 2024 12:41:54 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>,
 Lukasz Luba <lukasz.luba@....com>, Zhang Rui <rui.zhang@...el.com>
Subject:
 [RFC PATCH for 6.13 v1 13/20] thermal: core: Call
 thermal_governor_update_tz() outside of cdev lock

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Holding a cooling device lock around thermal_governor_update_tz() calls
is not necessary and it may cause lockdep to complain if any governor's
.update_tz() callback attempts to lock a cdev.

For this reason, move the thermal_governor_update_tz() calls in
thermal_bind_cdev_to_trip() and thermal_unbind_cdev_from_trip() from
under the cdev lock.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/thermal/thermal_core.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -825,13 +825,13 @@ static int thermal_bind_cdev_to_trip(str
 	if (!result) {
 		list_add_tail(&dev->trip_node, &td->thermal_instances);
 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
-
-		thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);
 	}
 	mutex_unlock(&cdev->lock);

-	if (!result)
+	if (!result) {
+		thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);
 		return 0;
+	}

 	device_remove_file(&tz->device, &dev->weight_attr);
 remove_trip_file:
@@ -866,9 +866,6 @@ static void thermal_unbind_cdev_from_tri
 		if (pos->cdev == cdev) {
 			list_del(&pos->trip_node);
 			list_del(&pos->cdev_node);
-
-			thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);
-
 			mutex_unlock(&cdev->lock);
 			goto unbind;
 		}
@@ -878,6 +875,8 @@ static void thermal_unbind_cdev_from_tri
 	return;

 unbind:
+	thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);
+
 	device_remove_file(&tz->device, &pos->weight_attr);
 	device_remove_file(&tz->device, &pos->attr);
 	sysfs_remove_link(&tz->device.kobj, pos->name);