[PATCH v2 7/8] ACPI: thermal: Rework thermal_get_trend()

Rafael J. Wysocki
2023-07-21T15:18:17Z

Rework the ACPI thermal driver's .get_trend() callback function,
thermal_get_trend(), to use trip point data stored in the generic
trip structures instead of calling thermal_get_trip_type() and
thermal_get_trip_temp().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2:
* Do not acquire thermal_check_lock in thermal_get_trend() (lockdep
would complain about this, because it is hold around thermal zone
locking and .get_trend() runs under the thermal zone lock). The
thermal zone locking added in the previous patches is sufficient
to protect this code.
* Check trips against invalid temperature values.
* Return an error for trips other than passive and active.

---
drivers/acpi/thermal.c | 106 ++++++++++++++++++++++++++++++++++++-------------
1 file changed, 78 insertions(+), 28 deletions(-)

Index: linux-pm/drivers/acpi/thermal.c
===================================================================
--- linux-pm.orig/drivers/acpi/thermal.c
+++ linux-pm/drivers/acpi/thermal.c
@@ -577,47 +577,97 @@ static int thermal_get_crit_temp(struct
return -EINVAL;
}

-static int thermal_get_trend(struct thermal_zone_device *thermal,
- int trip, enum thermal_trend *trend)
+static struct thermal_trip *acpi_thermal_get_trip(struct acpi_thermal *tz,
+ int trip_index)
{
- struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
- enum thermal_trip_type type;
+ struct thermal_trip *trip;
int i;

- if (thermal_get_trip_type(thermal, trip, &type))
- return -EINVAL;
+ if (!tz || trip_index < 0)
+ return NULL;

- if (type == THERMAL_TRIP_ACTIVE) {
- int trip_temp;
- int temp = deci_kelvin_to_millicelsius_with_offset(
- tz->temperature, tz->kelvin_offset);
- if (thermal_get_trip_temp(thermal, trip, &trip_temp))
- return -EINVAL;
+ trip = tz->trips.critical.trip_ref.trip;
+ if (trip) {
+ if (!trip_index)
+ return trip;

- if (temp > trip_temp) {
- *trend = THERMAL_TREND_RAISING;
- return 0;
- } else {
- /* Fall back on default trend */
- return -EINVAL;
+ trip_index--;
+ }
+
+ trip = tz->trips.hot.trip_ref.trip;
+ if (trip) {
+ if (!trip_index)
+ return trip;
+
+ trip_index--;
+ }
+
+ trip = tz->trips.passive.trip_ref.trip;
+ if (trip) {
+ if (!trip_index)
+ return trip;
+
+ trip_index--;
+ }
+
+ for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
+ trip = tz->trips.active[i].trip_ref.trip;
+ if (trip) {
+ if (!trip_index)
+ return trip;
+
+ trip_index--;
}
}

+ return NULL;
+}
+
+static int thermal_get_trend(struct thermal_zone_device *thermal,
+ int trip_index, enum thermal_trend *trend)
+{
+ struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
+ struct thermal_trip *trip;
+ long t;
+
+ trip = acpi_thermal_get_trip(tz, trip_index);
+ if (!trip || trip->temperature == THERMAL_TEMP_INVALID)
+ return -EINVAL;
+
/*
* tz->temperature has already been updated by generic thermal layer,
- * before this callback being invoked
+ * before this callback being invoked.
*/
- i = tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature) +
- tz->trips.passive.tc2 * (tz->temperature - tz->trips.passive.temperature);
+ switch (trip->type) {
+ case THERMAL_TRIP_PASSIVE:
+ t = tz->trips.passive.tc1 * (tz->temperature -
+ tz->last_temperature) +
+ tz->trips.passive.tc2 * (tz->temperature -
+ tz->trips.passive.temperature);
+ if (t > 0)
+ *trend = THERMAL_TREND_RAISING;
+ else if (t < 0)
+ *trend = THERMAL_TREND_DROPPING;
+ else
+ *trend = THERMAL_TREND_STABLE;
+
+ return 0;
+
+ case THERMAL_TRIP_ACTIVE:
+ t = deci_kelvin_to_millicelsius_with_offset(tz->temperature,
+ tz->kelvin_offset);
+ if (t > trip->temperature) {
+ *trend = THERMAL_TREND_RAISING;
+ return 0;
+ }

- if (i > 0)
- *trend = THERMAL_TREND_RAISING;
- else if (i < 0)
- *trend = THERMAL_TREND_DROPPING;
- else
- *trend = THERMAL_TREND_STABLE;
+ fallthrough;

- return 0;
+ default:
+ break;
+ }
+
+ return -EINVAL;
}

static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)