[PATCH v1 1/2] thermal: gov_fair_share: Fix dependency on trip points ordering

Rafael J. Wysocki
2024-01-15T17:57:40Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The computation in the fair share governor's get_trip_level() function
currently works under the assumption that the temperature ordering of
trips[] in a thermal zone is ascending, which need not be the case.

However, get_trip_level() can be made work regardless of whether or not
the trips table is ordered by temperature in any way, so change it
accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/thermal/gov_fair_share.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

Index: linux-pm/drivers/thermal/gov_fair_share.c
===================================================================
--- linux-pm.orig/drivers/thermal/gov_fair_share.c
+++ linux-pm/drivers/thermal/gov_fair_share.c
@@ -18,22 +18,24 @@
static int get_trip_level(struct thermal_zone_device *tz)
{
const struct thermal_trip *trip, *level_trip = NULL;
- int trip_level;
+ int trip_level = -1;

for_each_trip(tz, trip) {
if (trip->temperature >= tz->temperature)
- break;
+ continue;

- level_trip = trip;
+ trip_level++;
+
+ if (!level_trip || trip->temperature > level_trip->temperature)
+ level_trip = trip;
}

/* Bail out if the temperature is not greater than any trips. */
- if (!level_trip)
+ if (trip_level < 0)
return 0;

- trip_level = thermal_zone_trip_id(tz, level_trip);
-
- trace_thermal_zone_trip(tz, trip_level, level_trip->type);
+ trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, level_trip),
+ level_trip->type);

return trip_level;
}