diff mbox series

[v1] thermal: trip: Avoid skipping trips in thermal_zone_set_trips()

Message ID 12509184.O9o76ZdvQC@rjwysocki.net
State New
Headers show
Series [v1] thermal: trip: Avoid skipping trips in thermal_zone_set_trips() | expand

Commit Message

Rafael J. Wysocki July 30, 2024, 2:41 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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: 893bae92237d ("thermal: trip: Make thermal_zone_set_trips() use trip thresholds")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

6.11-rc material.

---
 drivers/thermal/thermal_trip.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

Index: linux-pm/drivers/thermal/thermal_trip.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_trip.c
+++ linux-pm/drivers/thermal/thermal_trip.c
@@ -82,10 +82,10 @@  void thermal_zone_set_trips(struct therm
 		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;
 	}