[PATCH v2 05/11] thermal: core: Call thermal_governor_update_tz() outside of cdev lock

Rafael J. Wysocki
2024-10-10T22:22:35Z

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

Holding a cooling device lock under thermal_governor_update_tz() 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@intel.com>
---

This is a resend of

https://lore.kernel.org/linux-pm/1921484.CQOukoFCf9@rjwysocki.net/

---
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
@@ -832,13 +832,13 @@ 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:
@@ -873,9 +873,6 @@ 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;
}
@@ -885,6 +882,8 @@ 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);