[PATCH v1] thermal: core: Clean up thermal_list_lock locking

Rafael J. Wysocki
2023-03-22T19:34:25Z

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

Once thermal_list_lock has been acquired in
__thermal_cooling_device_register(), it is not necessary to drop it
and take it again until all of the thermal zones have been updated,
so change the code accordingly.

No expected functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/thermal/thermal_core.c | 8 ++------
1 file changed, 2 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
@@ -826,8 +826,6 @@ static void bind_cdev(struct thermal_coo
const struct thermal_zone_params *tzp;
struct thermal_zone_device *pos = NULL;

- mutex_lock(&thermal_list_lock);
-
list_for_each_entry(pos, &thermal_tz_list, node) {
if (!pos->tzp && !pos->ops->bind)
continue;
@@ -854,8 +852,6 @@ static void bind_cdev(struct thermal_coo
tzp->tbp[i].weight);
}
}
-
- mutex_unlock(&thermal_list_lock);
}

/**
@@ -933,17 +929,17 @@ __thermal_cooling_device_register(struct

/* Add 'this' new cdev to the global cdev list */
mutex_lock(&thermal_list_lock);
+
list_add(&cdev->node, &thermal_cdev_list);
- mutex_unlock(&thermal_list_lock);

/* Update binding information for 'this' new cdev */
bind_cdev(cdev);

- mutex_lock(&thermal_list_lock);
list_for_each_entry(pos, &thermal_tz_list, node)
if (atomic_cmpxchg(&pos->need_update, 1, 0))
thermal_zone_device_update(pos,
THERMAL_EVENT_UNSPECIFIED);
+
mutex_unlock(&thermal_list_lock);

return cdev;