[PATCH 12/30] Thermal: Unify the code for both active and passive cooling

From: Len Brown
Date: Tue Oct 09 2012 - 02:09:31 EST


From: Zhang Rui <rui.zhang@xxxxxxxxx>

Remove thermal_zone_device_passive(). And use
thermal_zone_trip_update() and thermal_zone_do_update()
for both active and passive cooling.

Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rjw@xxxxxxx>
Reviewed-by: Eduardo Valentin <eduardo.valentin@xxxxxx>
---
drivers/thermal/thermal_sys.c | 110 ++++++++++--------------------------------
include/linux/thermal.h | 2 +-
2 files changed, 26 insertions(+), 86 deletions(-)

diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 36ae2f4..6e9d3dc 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -715,84 +715,6 @@ static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
msecs_to_jiffies(delay));
}

-static void thermal_zone_device_passive(struct thermal_zone_device *tz,
- int temp, int trip_temp, int trip)
-{
- enum thermal_trend trend;
- struct thermal_instance *instance;
- struct thermal_cooling_device *cdev;
- long state, max_state;
-
- if (!tz->ops->get_trend || tz->ops->get_trend(tz, trip, &trend)) {
- /*
- * compare the current temperature and previous temperature
- * to get the thermal trend, if no special requirement
- */
- if (tz->temperature > tz->last_temperature)
- trend = THERMAL_TREND_RAISING;
- else if (tz->temperature < tz->last_temperature)
- trend = THERMAL_TREND_DROPPING;
- else
- trend = THERMAL_TREND_STABLE;
- }
-
- /*
- * Above Trip?
- * -----------
- * Calculate the thermal trend (using the passive cooling equation)
- * and modify the performance limit for all passive cooling devices
- * accordingly. Note that we assume symmetry.
- */
- if (temp >= trip_temp) {
- tz->passive = true;
-
- /* Heating up? */
- if (trend == THERMAL_TREND_RAISING) {
- list_for_each_entry(instance, &tz->thermal_instances,
- tz_node) {
- if (instance->trip != trip)
- continue;
- cdev = instance->cdev;
- cdev->ops->get_cur_state(cdev, &state);
- cdev->ops->get_max_state(cdev, &max_state);
- if (state++ < max_state)
- cdev->ops->set_cur_state(cdev, state);
- }
- } else if (trend == THERMAL_TREND_DROPPING) { /* Cooling off? */
- list_for_each_entry(instance, &tz->thermal_instances,
- tz_node) {
- if (instance->trip != trip)
- continue;
- cdev = instance->cdev;
- cdev->ops->get_cur_state(cdev, &state);
- cdev->ops->get_max_state(cdev, &max_state);
- if (state > 0)
- cdev->ops->set_cur_state(cdev, --state);
- }
- }
- return;
- }
-
- /*
- * Below Trip?
- * -----------
- * Implement passive cooling hysteresis to slowly increase performance
- * and avoid thrashing around the passive trip point. Note that we
- * assume symmetry.
- */
- list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
- if (instance->trip != trip)
- continue;
- cdev = instance->cdev;
- cdev->ops->get_cur_state(cdev, &state);
- cdev->ops->get_max_state(cdev, &max_state);
- if (state > 0)
- cdev->ops->set_cur_state(cdev, --state);
- if (state == 0)
- tz->passive = false;
- }
-}
-
static void thermal_zone_device_check(struct work_struct *work)
{
struct thermal_zone_device *tz = container_of(work, struct
@@ -1114,7 +1036,7 @@ static void thermal_zone_do_update(struct thermal_zone_device *tz)
}

/*
- * Cooling algorithm for active trip points
+ * Cooling algorithm for both active and passive cooling
*
* 1. if the temperature is higher than a trip point,
* a. if the trend is THERMAL_TREND_RAISING, use higher cooling
@@ -1136,9 +1058,16 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev = NULL;
unsigned long cur_state, max_state;
long trip_temp;
+ enum thermal_trip_type trip_type;
enum thermal_trend trend;

- tz->ops->get_trip_temp(tz, trip, &trip_temp);
+ if (trip == THERMAL_TRIPS_NONE) {
+ trip_temp = tz->forced_passive;
+ trip_type = THERMAL_TRIPS_NONE;
+ } else {
+ tz->ops->get_trip_temp(tz, trip, &trip_temp);
+ tz->ops->get_trip_type(tz, trip, &trip_type);
+ }

if (!tz->ops->get_trend || tz->ops->get_trend(tz, trip, &trend)) {
/*
@@ -1170,6 +1099,13 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz,
cur_state = cur_state > instance->lower ?
(cur_state - 1) : instance->lower;
}
+
+ /* activate a passive thermal instance */
+ if ((trip_type == THERMAL_TRIP_PASSIVE ||
+ trip_type == THERMAL_TRIPS_NONE) &&
+ instance->target == THERMAL_NO_TARGET)
+ tz->passive++;
+
instance->target = cur_state;
cdev->updated = false; /* cooling device needs update */
}
@@ -1186,6 +1122,12 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz,

cur_state = cur_state > instance->lower ?
(cur_state - 1) : THERMAL_NO_TARGET;
+
+ /* deactivate a passive thermal instance */
+ if ((trip_type == THERMAL_TRIP_PASSIVE ||
+ trip_type == THERMAL_TRIPS_NONE) &&
+ cur_state == THERMAL_NO_TARGET)
+ tz->passive--;
instance->target = cur_state;
cdev->updated = false; /* cooling device needs update */
}
@@ -1242,16 +1184,14 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
break;
case THERMAL_TRIP_PASSIVE:
if (temp >= trip_temp || tz->passive)
- thermal_zone_device_passive(tz, temp,
- trip_temp, count);
+ thermal_zone_trip_update(tz, count, temp);
break;
}
}

- thermal_zone_do_update(tz);
if (tz->forced_passive)
- thermal_zone_device_passive(tz, temp, tz->forced_passive,
- THERMAL_TRIPS_NONE);
+ thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE, temp);
+ thermal_zone_do_update(tz);

leave:
if (tz->passive)
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index de0515a..76d0fe8 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -121,7 +121,7 @@ struct thermal_zone_device {
int polling_delay;
int temperature;
int last_temperature;
- bool passive;
+ int passive;
unsigned int forced_passive;
const struct thermal_zone_device_ops *ops;
struct list_head thermal_instances;
--
1.8.0.rc1

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