thermal/debugfs: Print initial trip temperature and hysteresis in tze_seq_show()

The temperature and hysteresis of a trip point may change during a
mitigation episode it is involved in (it may even become invalid
altogether), so in order to avoid possible confusion related to that,
store the temperature and hysteresis of trip points at the time they
are crossed on the way up and print those values instead of their
current temperature and hysteresis.

Fixes: 7ef01f22 ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/thermal/thermal_debugfs.c

@@ -91,6 +91,8 @@ struct cdev_record {
  *
  * @timestamp: the trip crossing timestamp
  * @duration: total time when the zone temperature was above the trip point
+ * @trip_temp: trip temperature at mitigation start
+ * @trip_hyst: trip hysteresis at mitigation start
  * @count: the number of times the zone temperature was above the trip point
  * @max: maximum recorded temperature above the trip point
  * @min: minimum recorded temperature above the trip point
@@ -99,6 +101,8 @@ struct cdev_record {
 struct trip_stats {
 	ktime_t timestamp;
 	ktime_t duration;
+	int trip_temp;
+	int trip_hyst;
 	int count;
 	int max;
 	int min;
@@ -574,6 +578,7 @@ void thermal_debug_tz_trip_up(struct thermal_zone_device *tz,
 	struct thermal_debugfs *thermal_dbg = tz->debugfs;
 	int trip_id = thermal_zone_trip_id(tz, trip);
 	ktime_t now = ktime_get();
+	struct trip_stats *trip_stats;
 
 	if (!thermal_dbg)
 		return;
@@ -639,7 +644,10 @@ void thermal_debug_tz_trip_up(struct thermal_zone_device *tz,
 	tz_dbg->trips_crossed[tz_dbg->nr_trips++] = trip_id;
 
 	tze = list_first_entry(&tz_dbg->tz_episodes, struct tz_episode, node);
-	tze->trip_stats[trip_id].timestamp = now;
+	trip_stats = &tze->trip_stats[trip_id];
+	trip_stats->trip_temp = trip->temperature;
+	trip_stats->trip_hyst = trip->hysteresis;
+	trip_stats->timestamp = now;
 
 unlock:
 	mutex_unlock(&thermal_dbg->lock);
@@ -836,8 +844,8 @@ static int tze_seq_show(struct seq_file *s, void *v)
 		seq_printf(s, "| %*d | %*s | %*d | %*d | %c%*lld | %*d | %*d | %*d |\n",
 			   4 , trip_id,
 			   8, type,
-			   9, trip->temperature,
-			   9, trip->hysteresis,
+			   9, trip_stats->trip_temp,
+			   9, trip_stats->trip_hyst,
 			   c, 10, duration_ms,
 			   9, trip_stats->avg,
 			   9, trip_stats->min,