thermal: core: Update thermal zones after cooling device binding

If a new cooling device is registered and it is bound to at least one
trip point in a given thermal zone, that thermal zone needs to be
updated via __thermal_zone_device_update().

Instead of doing this with the help of the need_update atomic field in
struct thermal_zone_device, which is not particularly straightforward,
make __thermal_zone_cdev_bind() return a bool value indicating whether
or not the given thermal zone needs to be updated because a new cooling
device has been bound to it and update thermal_zone_cdev_bind() to
call __thermal_zone_device_update() when this value is "true".

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2226302.Icojqenx9y@rjwysocki.net
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 145b43a4dffd71845fcb8fcbd73bc858fc3dffb9..b8c3a9185ae72727046420dd8ed87a4aedab5794 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -935,13 +935,14 @@ void print_bind_err_msg(struct thermal_zone_device *tz,
                cdev->type, thermal_zone_trip_id(tz, trip), ret);
 }
 
-static void __thermal_zone_cdev_bind(struct thermal_zone_device *tz,
+static bool __thermal_zone_cdev_bind(struct thermal_zone_device *tz,
                                     struct thermal_cooling_device *cdev)
 {
        struct thermal_trip_desc *td;
+       bool update_tz = false;
 
        if (!tz->ops.should_bind)
-               return;
+               return false;
 
        for_each_trip_desc(tz, td) {
                struct thermal_trip *trip = &td->trip;
@@ -956,9 +957,15 @@ static void __thermal_zone_cdev_bind(struct thermal_zone_device *tz,
                        continue;
 
                ret = thermal_bind_cdev_to_trip(tz, trip, cdev, &c);
-               if (ret)
+               if (ret) {
                        print_bind_err_msg(tz, trip, cdev, ret);
+                       continue;
+               }
+
+               update_tz = true;
        }
+
+       return update_tz;
 }
 
 static void thermal_zone_cdev_bind(struct thermal_zone_device *tz,
@@ -966,7 +973,8 @@ static void thermal_zone_cdev_bind(struct thermal_zone_device *tz,
 {
        mutex_lock(&tz->lock);
 
-       __thermal_zone_cdev_bind(tz, cdev);
+       if (__thermal_zone_cdev_bind(tz, cdev))
+               __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 
        mutex_unlock(&tz->lock);
 }
@@ -993,7 +1001,7 @@ __thermal_cooling_device_register(struct device_node *np,
                                  const struct thermal_cooling_device_ops *ops)
 {
        struct thermal_cooling_device *cdev;
-       struct thermal_zone_device *pos = NULL;
+       struct thermal_zone_device *pos;
        unsigned long current_state;
        int id, ret;
 
@@ -1069,11 +1077,6 @@ __thermal_cooling_device_register(struct device_node *np,
        list_for_each_entry(pos, &thermal_tz_list, node)
                thermal_zone_cdev_bind(pos, cdev);
 
-       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;