diff options
| -rw-r--r-- | Documentation/thermal/power_allocator.txt | 2 | ||||
| -rw-r--r-- | drivers/thermal/power_allocator.c | 101 |
2 files changed, 58 insertions, 45 deletions
diff --git a/Documentation/thermal/power_allocator.txt b/Documentation/thermal/power_allocator.txt index c3797b529991..a1ce2235f121 100644 --- a/Documentation/thermal/power_allocator.txt +++ b/Documentation/thermal/power_allocator.txt @@ -4,7 +4,7 @@ Power allocator governor tunables Trip points ----------- -The governor requires the following two passive trip points: +The governor works optimally with the following two passive trip points: 1. "switch on" trip point: temperature above which the governor control loop starts operating. This is the first passive trip diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index 51473473f154..ea57759eb095 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) @@ -61,6 +63,8 @@ static inline s64 div_frac(s64 x, s64 y) * 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. @@ -432,43 +436,66 @@ 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) @@ -497,11 +524,10 @@ 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 + * Return: 0 on success, -EINVAL if the thermal zone doesn't have tzp or -ENOMEM * if we ran out of memory. */ static int power_allocator_bind(struct thermal_zone_device *tz) @@ -520,30 +546,23 @@ static int power_allocator_bind(struct thermal_zone_device *tz) if (!tz->tzp->sustainable_power) dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); - 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; - } + get_governor_trips(tz, params); - ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, - &control_temp); - if (ret) - goto free; + 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); + } - estimate_pid_constants(tz, tz->tzp->sustainable_power, - params->trip_switch_on, control_temp, false); reset_pid_controller(params); tz->governor_data = params; return 0; - -free: - kfree(params); - return ret; } static void power_allocator_unbind(struct thermal_zone_device *tz) @@ -574,13 +593,7 @@ 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); |