thermal: sysfs: Rework the handling of trip point updates

Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it.  However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.

Moreover, input processing need not be done under the thermal zone lock
in any of these functions.

Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.

While at it, make trip_point_hyst_store() reject negative hysteresis
values.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 9 insertions, 36 deletions

diff --git a/drivers/thermal/thermal_trip.c b/drivers/thermal/thermal_trip.c
index e3dd583234dd..90861dec7eb0 100644
--- a/drivers/thermal/thermal_trip.c
+++ b/drivers/thermal/thermal_trip.c
@@ -147,42 +147,6 @@ int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 }
 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
 
-int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
-			  const struct thermal_trip *trip)
-{
-	struct thermal_trip t;
-	int ret;
-
-	ret = __thermal_zone_get_trip(tz, trip_id, &t);
-	if (ret)
-		return ret;
-
-	if (t.type != trip->type)
-		return -EINVAL;
-
-	if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
-		ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
-		if (ret)
-			return ret;
-	}
-
-	if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
-		ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
-		if (ret)
-			return ret;
-	}
-
-	if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
-		tz->trips[trip_id] = *trip;
-
-	thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
-				      trip->temperature, trip->hysteresis);
-
-	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
-
-	return 0;
-}
-
 int thermal_zone_trip_id(struct thermal_zone_device *tz,
 			 const struct thermal_trip *trip)
 {
@@ -192,3 +156,12 @@ int thermal_zone_trip_id(struct thermal_zone_device *tz,
 	 */
 	return trip - tz->trips;
 }
+
+void thermal_zone_trip_updated(struct thermal_zone_device *tz,
+			       const struct thermal_trip *trip)
+{
+	thermal_notify_tz_trip_change(tz->id, thermal_zone_trip_id(tz, trip),
+				      trip->type, trip->temperature,
+				      trip->hysteresis);
+	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
+}