thermal: trip: Avoid skipping trips in thermal_zone_set_trips()

Say there are 3 trip points A, B, C sorted in ascending temperature
order with no hysteresis.  If the zone temerature is exactly equal to
B, thermal_zone_set_trips() will set the boundaries to A and C and the
hardware will not catch any crossing of B (either way) until either A
or C is crossed and the boundaries are changed.

To avoid that, use non-strict inequalities when comparing the trip
threshold to the zone temperature in thermal_zone_set_trips().

In the example above, it will cause both boundaries to be set to B,
which is desirable because an interrupt will trigger when the zone
temperature becomes different from B regardless of which way it goes.
That will allow a new interval to be set depending on the direction of
the zone temperature change.

Fixes: 893bae9 ("thermal: trip: Make thermal_zone_set_trips() use trip thresholds")
Signed-off-by: Rafael J. Wysocki <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: rafaeljw

drivers/thermal/thermal_trip.c

@@ -88,10 +88,10 @@ void thermal_zone_set_trips(struct thermal_zone_device *tz)
 		return;
 
 	for_each_trip_desc(tz, td) {
-		if (td->threshold < tz->temperature && td->threshold > low)
+		if (td->threshold <= tz->temperature && td->threshold > low)
 			low = td->threshold;
 
-		if (td->threshold > tz->temperature && td->threshold < high)
+		if (td->threshold >= tz->temperature && td->threshold < high)
 			high = td->threshold;
 	}