From 8c69a777e480174b1fdd75dab5ad584454dd6555 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 17 May 2024 11:24:03 +0200 Subject: [PATCH] thermal: core: Fix the handling of invalid trip points Commit 9ad18043fb35 ("thermal: core: Send trip crossing notifications at init time if needed") overlooked the case when a trip point that has started as invalid is set to a valid temperature later. Namely, the initial threshold value for all trips is zero, so if a previously invalid trip becomes valid and its (new) low temperature is above the zone temperature, a spurious trip crossing notification will occur and it may trigger the WARN_ON() in handle_thermal_trip(). To address this, set the initial threshold for all trips to INT_MAX. There is also the case when a valid writable trip becomes invalid that requires special handling. First, in accordance with the change mentioned above, the trip's threshold needs to be set to INT_MAX to avoid the same issue. Second, if the trip in question is passive and it has been crossed by the thermal zone temperature on the way up, the zone's passive count has been incremented and it is in the passive polling mode, so its passive count needs to be adjusted to allow the passive polling to be turned off eventually. Fixes: 9ad18043fb35 ("thermal: core: Send trip crossing notifications at init time if needed") Fixes: 042a3d80f118 ("thermal: core: Move passive polling management to the core") Reported-by: Zhang Rui Signed-off-by: Rafael J. Wysocki Tested-by: Wendy Wang --- drivers/thermal/thermal_core.c | 9 ++++++++- drivers/thermal/thermal_trip.c | 18 ++++++++++++++++++ 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 11750a145d74..54cce4e523bc 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1398,8 +1398,15 @@ thermal_zone_device_register_with_trips(const char *type, tz->device.class = thermal_class; tz->devdata = devdata; tz->num_trips = num_trips; - for_each_trip_desc(tz, td) + for_each_trip_desc(tz, td) { td->trip = *trip++; + /* + * Mark all thresholds as invalid to start with even though + * this only matters for the trips that start as invalid and + * become valid later. + */ + td->threshold = INT_MAX; + } thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay); thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay); diff --git a/drivers/thermal/thermal_trip.c b/drivers/thermal/thermal_trip.c index 21ece8399997..d6a6acc78ddb 100644 --- a/drivers/thermal/thermal_trip.c +++ b/drivers/thermal/thermal_trip.c @@ -152,6 +152,24 @@ void thermal_zone_set_trip_temp(struct thermal_zone_device *tz, if (trip->temperature == temp) return; + if (temp == THERMAL_TEMP_INVALID) { + struct thermal_trip_desc *td = trip_to_trip_desc(trip); + + if (trip->type == THERMAL_TRIP_PASSIVE && + tz->temperature >= td->threshold) { + /* + * The trip has been crossed, so the thermal zone's + * passive count needs to be adjusted. + */ + tz->passive--; + WARN_ON_ONCE(tz->passive < 0); + } + /* + * Invalidate the threshold to avoid triggering a spurious + * trip crossing notification when the trip becomes valid. + */ + td->threshold = INT_MAX; + } trip->temperature = temp; thermal_notify_tz_trip_change(tz, trip); }