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authorTakashi Iwai <tiwai@suse.de>2015-10-07 20:11:21 +0200
committerTakashi Iwai <tiwai@suse.de>2015-10-07 20:11:21 +0200
commit601d62959d08a450d4666c728ddd2f47c5ba1cfe (patch)
tree52d9f3c1a2528a9de405d5a19014f3f94b16b35d /drivers/thermal/power_allocator.c
parent225db5762dc1a35b26850477ffa06e5cd0097243 (diff)
parente4fc141d2a022a63c87a4851b3c688eca6a1647b (diff)
Merge tag 'asoc-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v4.3 Quite a few fixes here but they're all very small and driver specific, none of them really stand out if you aren't using the relevant hardware but they're all useful if you do happen to have an affected device.
Diffstat (limited to 'drivers/thermal/power_allocator.c')
-rw-r--r--drivers/thermal/power_allocator.c253
1 files changed, 189 insertions, 64 deletions
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
index 9c8a7aad0252..e570ff084add 100644
--- a/drivers/thermal/power_allocator.c
+++ b/drivers/thermal/power_allocator.c
@@ -24,6 +24,8 @@
#include "thermal_core.h"
+#define INVALID_TRIP -1
+
#define FRAC_BITS 10
#define int_to_frac(x) ((x) << FRAC_BITS)
#define frac_to_int(x) ((x) >> FRAC_BITS)
@@ -56,16 +58,21 @@ static inline s64 div_frac(s64 x, s64 y)
/**
* struct power_allocator_params - parameters for the power allocator governor
+ * @allocated_tzp: whether we have allocated tzp for this thermal zone and
+ * it needs to be freed on unbind
* @err_integral: accumulated error in the PID controller.
* @prev_err: error in the previous iteration of the PID controller.
* Used to calculate the derivative term.
* @trip_switch_on: first passive trip point of the thermal zone. The
* governor switches on when this trip point is crossed.
+ * If the thermal zone only has one passive trip point,
+ * @trip_switch_on should be INVALID_TRIP.
* @trip_max_desired_temperature: last passive trip point of the thermal
* zone. The temperature we are
* controlling for.
*/
struct power_allocator_params {
+ bool allocated_tzp;
s64 err_integral;
s32 prev_err;
int trip_switch_on;
@@ -73,6 +80,98 @@ struct power_allocator_params {
};
/**
+ * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone
+ * @tz: thermal zone we are operating in
+ *
+ * For thermal zones that don't provide a sustainable_power in their
+ * thermal_zone_params, estimate one. Calculate it using the minimum
+ * power of all the cooling devices as that gives a valid value that
+ * can give some degree of functionality. For optimal performance of
+ * this governor, provide a sustainable_power in the thermal zone's
+ * thermal_zone_params.
+ */
+static u32 estimate_sustainable_power(struct thermal_zone_device *tz)
+{
+ u32 sustainable_power = 0;
+ struct thermal_instance *instance;
+ struct power_allocator_params *params = tz->governor_data;
+
+ list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+ struct thermal_cooling_device *cdev = instance->cdev;
+ u32 min_power;
+
+ if (instance->trip != params->trip_max_desired_temperature)
+ continue;
+
+ if (power_actor_get_min_power(cdev, tz, &min_power))
+ continue;
+
+ sustainable_power += min_power;
+ }
+
+ return sustainable_power;
+}
+
+/**
+ * estimate_pid_constants() - Estimate the constants for the PID controller
+ * @tz: thermal zone for which to estimate the constants
+ * @sustainable_power: sustainable power for the thermal zone
+ * @trip_switch_on: trip point number for the switch on temperature
+ * @control_temp: target temperature for the power allocator governor
+ * @force: whether to force the update of the constants
+ *
+ * This function is used to update the estimation of the PID
+ * controller constants in struct thermal_zone_parameters.
+ * Sustainable power is provided in case it was estimated. The
+ * estimated sustainable_power should not be stored in the
+ * thermal_zone_parameters so it has to be passed explicitly to this
+ * function.
+ *
+ * If @force is not set, the values in the thermal zone's parameters
+ * are preserved if they are not zero. If @force is set, the values
+ * in thermal zone's parameters are overwritten.
+ */
+static void estimate_pid_constants(struct thermal_zone_device *tz,
+ u32 sustainable_power, int trip_switch_on,
+ int control_temp, bool force)
+{
+ int ret;
+ int switch_on_temp;
+ u32 temperature_threshold;
+
+ ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp);
+ if (ret)
+ switch_on_temp = 0;
+
+ temperature_threshold = control_temp - switch_on_temp;
+ /*
+ * estimate_pid_constants() tries to find appropriate default
+ * values for thermal zones that don't provide them. If a
+ * system integrator has configured a thermal zone with two
+ * passive trip points at the same temperature, that person
+ * hasn't put any effort to set up the thermal zone properly
+ * so just give up.
+ */
+ if (!temperature_threshold)
+ return;
+
+ if (!tz->tzp->k_po || force)
+ tz->tzp->k_po = int_to_frac(sustainable_power) /
+ temperature_threshold;
+
+ if (!tz->tzp->k_pu || force)
+ tz->tzp->k_pu = int_to_frac(2 * sustainable_power) /
+ temperature_threshold;
+
+ if (!tz->tzp->k_i || force)
+ tz->tzp->k_i = int_to_frac(10) / 1000;
+ /*
+ * The default for k_d and integral_cutoff is 0, so we can
+ * leave them as they are.
+ */
+}
+
+/**
* pid_controller() - PID controller
* @tz: thermal zone we are operating in
* @current_temp: the current temperature in millicelsius
@@ -98,10 +197,20 @@ static u32 pid_controller(struct thermal_zone_device *tz,
{
s64 p, i, d, power_range;
s32 err, max_power_frac;
+ u32 sustainable_power;
struct power_allocator_params *params = tz->governor_data;
max_power_frac = int_to_frac(max_allocatable_power);
+ if (tz->tzp->sustainable_power) {
+ sustainable_power = tz->tzp->sustainable_power;
+ } else {
+ sustainable_power = estimate_sustainable_power(tz);
+ estimate_pid_constants(tz, sustainable_power,
+ params->trip_switch_on, control_temp,
+ true);
+ }
+
err = control_temp - current_temp;
err = int_to_frac(err);
@@ -139,7 +248,7 @@ static u32 pid_controller(struct thermal_zone_device *tz,
power_range = p + i + d;
/* feed-forward the known sustainable dissipatable power */
- power_range = tz->tzp->sustainable_power + frac_to_int(power_range);
+ power_range = sustainable_power + frac_to_int(power_range);
power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power);
@@ -247,6 +356,11 @@ static int allocate_power(struct thermal_zone_device *tz,
}
}
+ if (!num_actors) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
/*
* We need to allocate five arrays of the same size:
* req_power, max_power, granted_power, extra_actor_power and
@@ -340,43 +454,66 @@ unlock:
return ret;
}
-static int get_governor_trips(struct thermal_zone_device *tz,
- struct power_allocator_params *params)
+/**
+ * get_governor_trips() - get the number of the two trip points that are key for this governor
+ * @tz: thermal zone to operate on
+ * @params: pointer to private data for this governor
+ *
+ * The power allocator governor works optimally with two trips points:
+ * a "switch on" trip point and a "maximum desired temperature". These
+ * are defined as the first and last passive trip points.
+ *
+ * If there is only one trip point, then that's considered to be the
+ * "maximum desired temperature" trip point and the governor is always
+ * on. If there are no passive or active trip points, then the
+ * governor won't do anything. In fact, its throttle function
+ * won't be called at all.
+ */
+static void get_governor_trips(struct thermal_zone_device *tz,
+ struct power_allocator_params *params)
{
- int i, ret, last_passive;
+ int i, last_active, last_passive;
bool found_first_passive;
found_first_passive = false;
- last_passive = -1;
- ret = -EINVAL;
+ last_active = INVALID_TRIP;
+ last_passive = INVALID_TRIP;
for (i = 0; i < tz->trips; i++) {
enum thermal_trip_type type;
+ int ret;
ret = tz->ops->get_trip_type(tz, i, &type);
- if (ret)
- return ret;
+ if (ret) {
+ dev_warn(&tz->device,
+ "Failed to get trip point %d type: %d\n", i,
+ ret);
+ continue;
+ }
- if (!found_first_passive) {
- if (type == THERMAL_TRIP_PASSIVE) {
+ if (type == THERMAL_TRIP_PASSIVE) {
+ if (!found_first_passive) {
params->trip_switch_on = i;
found_first_passive = true;
+ } else {
+ last_passive = i;
}
- } else if (type == THERMAL_TRIP_PASSIVE) {
- last_passive = i;
+ } else if (type == THERMAL_TRIP_ACTIVE) {
+ last_active = i;
} else {
break;
}
}
- if (last_passive != -1) {
+ if (last_passive != INVALID_TRIP) {
params->trip_max_desired_temperature = last_passive;
- ret = 0;
+ } else if (found_first_passive) {
+ params->trip_max_desired_temperature = params->trip_switch_on;
+ params->trip_switch_on = INVALID_TRIP;
} else {
- ret = -EINVAL;
+ params->trip_switch_on = INVALID_TRIP;
+ params->trip_max_desired_temperature = last_active;
}
-
- return ret;
}
static void reset_pid_controller(struct power_allocator_params *params)
@@ -405,60 +542,45 @@ static void allow_maximum_power(struct thermal_zone_device *tz)
* power_allocator_bind() - bind the power_allocator governor to a thermal zone
* @tz: thermal zone to bind it to
*
- * Check that the thermal zone is valid for this governor, that is, it
- * has two thermal trips. If so, initialize the PID controller
- * parameters and bind it to the thermal zone.
+ * Initialize the PID controller parameters and bind it to the thermal
+ * zone.
*
- * Return: 0 on success, -EINVAL if the trips were invalid or -ENOMEM
- * if we ran out of memory.
+ * Return: 0 on success, or -ENOMEM if we ran out of memory.
*/
static int power_allocator_bind(struct thermal_zone_device *tz)
{
int ret;
struct power_allocator_params *params;
- int switch_on_temp, control_temp;
- u32 temperature_threshold;
-
- if (!tz->tzp || !tz->tzp->sustainable_power) {
- dev_err(&tz->device,
- "power_allocator: missing sustainable_power\n");
- return -EINVAL;
- }
+ int control_temp;
params = kzalloc(sizeof(*params), GFP_KERNEL);
if (!params)
return -ENOMEM;
- ret = get_governor_trips(tz, params);
- if (ret) {
- dev_err(&tz->device,
- "thermal zone %s has wrong trip setup for power allocator\n",
- tz->type);
- goto free;
- }
+ if (!tz->tzp) {
+ tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL);
+ if (!tz->tzp) {
+ ret = -ENOMEM;
+ goto free_params;
+ }
- ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
- &switch_on_temp);
- if (ret)
- goto free;
+ params->allocated_tzp = true;
+ }
- ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature,
- &control_temp);
- if (ret)
- goto free;
+ if (!tz->tzp->sustainable_power)
+ dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n");
- temperature_threshold = control_temp - switch_on_temp;
+ get_governor_trips(tz, params);
- tz->tzp->k_po = tz->tzp->k_po ?:
- int_to_frac(tz->tzp->sustainable_power) / temperature_threshold;
- tz->tzp->k_pu = tz->tzp->k_pu ?:
- int_to_frac(2 * tz->tzp->sustainable_power) /
- temperature_threshold;
- tz->tzp->k_i = tz->tzp->k_i ?: int_to_frac(10) / 1000;
- /*
- * The default for k_d and integral_cutoff is 0, so we can
- * leave them as they are.
- */
+ if (tz->trips > 0) {
+ ret = tz->ops->get_trip_temp(tz,
+ params->trip_max_desired_temperature,
+ &control_temp);
+ if (!ret)
+ estimate_pid_constants(tz, tz->tzp->sustainable_power,
+ params->trip_switch_on,
+ control_temp, false);
+ }
reset_pid_controller(params);
@@ -466,14 +588,23 @@ static int power_allocator_bind(struct thermal_zone_device *tz)
return 0;
-free:
+free_params:
kfree(params);
+
return ret;
}
static void power_allocator_unbind(struct thermal_zone_device *tz)
{
+ struct power_allocator_params *params = tz->governor_data;
+
dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
+
+ if (params->allocated_tzp) {
+ kfree(tz->tzp);
+ tz->tzp = NULL;
+ }
+
kfree(tz->governor_data);
tz->governor_data = NULL;
}
@@ -499,13 +630,7 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
&switch_on_temp);
- if (ret) {
- dev_warn(&tz->device,
- "Failed to get switch on temperature: %d\n", ret);
- return ret;
- }
-
- if (current_temp < switch_on_temp) {
+ if (!ret && (current_temp < switch_on_temp)) {
tz->passive = 0;
reset_pid_controller(params);
allow_maximum_power(tz);