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Thermal: Unify the code for both active and passive cooling
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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@intel.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Eduardo Valentin <eduardo.valentin@ti.com>
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Zhang Rui committed Sep 24, 2012
1 parent ce119f8 commit 908b9fb
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Showing 2 changed files with 26 additions and 86 deletions.
110 changes: 25 additions & 85 deletions drivers/thermal/thermal_sys.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand All @@ -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)) {
/*
Expand Down Expand Up @@ -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 */
}
Expand All @@ -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 */
}
Expand Down Expand Up @@ -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)
Expand Down
2 changes: 1 addition & 1 deletion include/linux/thermal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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