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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
 "Rafael J. Wysocki" <rafael@kernel.org>, Lukasz Luba <lukasz.luba@arm.com>,
 Daniel Lezcano <daniel.lezcano@linaro.org>,
 Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
 Zhang Rui <rui.zhang@intel.com>
Subject:
 [PATCH v1 3/6] thermal: trip: Make thermal_zone_set_trips() use trip
 thresholds
Date: Fri, 10 May 2024 16:16:52 +0200
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify thermal_zone_set_trips() to use trip thresholds instead of
computing the low temperature for each trip to avoid deriving both
the high and low temperature levels from the same trip (which may
happen if the zone temperature falls into the hysteresis range of
one trip).

Accordingly, make __thermal_zone_device_update() call
thermal_zone_set_trips() later, when threshold values have
been updated for all trips.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/thermal/thermal_core.c |    4 ++--
 drivers/thermal/thermal_trip.c |   14 ++++----------
 2 files changed, 6 insertions(+), 12 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -498,13 +498,13 @@ void __thermal_zone_device_update(struct
 	if (tz->temperature == THERMAL_TEMP_INVALID)
 		return;
 
-	thermal_zone_set_trips(tz);
-
 	tz->notify_event = event;
 
 	for_each_trip_desc(tz, td)
 		handle_thermal_trip(tz, td, &way_up_list, &way_down_list);
 
+	thermal_zone_set_trips(tz);
+
 	list_sort(&way_up_list, &way_up_list, thermal_trip_notify_cmp);
 	list_for_each_entry(td, &way_up_list, notify_list_node) {
 		thermal_notify_tz_trip_up(tz, &td->trip);
Index: linux-pm/drivers/thermal/thermal_trip.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_trip.c
+++ linux-pm/drivers/thermal/thermal_trip.c
@@ -88,17 +88,11 @@ void thermal_zone_set_trips(struct therm
 		return;
 
 	for_each_trip_desc(tz, td) {
-		const struct thermal_trip *trip = &td->trip;
-		int trip_low;
+		if (td->threshold < tz->temperature && td->threshold > low)
+			low = td->threshold;
 
-		trip_low = trip->temperature - trip->hysteresis;
-
-		if (trip_low < tz->temperature && trip_low > low)
-			low = trip_low;
-
-		if (trip->temperature > tz->temperature &&
-		    trip->temperature < high)
-			high = trip->temperature;
+		if (td->threshold > tz->temperature && td->threshold < high)
+			high = td->threshold;
 	}
 
 	/* No need to change trip points */