diff options
| -rw-r--r-- | Documentation/thermal/sysfs-api.txt | 12 | ||||
| -rw-r--r-- | drivers/thermal/fair_share.c | 26 | ||||
| -rw-r--r-- | include/linux/thermal.h | 9 |
3 files changed, 36 insertions, 11 deletions
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index 3625453ceef6..fc7dfe10778b 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -129,9 +129,15 @@ temperature) and throttle appropriate devices. This structure defines the following parameters that are used to bind a zone with a cooling device for a particular trip point. .cdev: The cooling device pointer - .weight: The 'influence' of a particular cooling device on this zone. - This is on a percentage scale. The sum of all these weights - (for a particular zone) cannot exceed 100. + .weight: The 'influence' of a particular cooling device on this + zone. This is relative to the rest of the cooling + devices. For example, if all cooling devices have a + weight of 1, then they all contribute the same. You can + use percentages if you want, but it's not mandatory. A + weight of 0 means that this cooling device doesn't + contribute to the cooling of this zone unless all cooling + devices have a weight of 0. If all weights are 0, then + they all contribute the same. .trip_mask:This is a bit mask that gives the binding relation between this thermal zone and cdev, for a particular trip point. If nth bit is set, then the cdev and thermal zone are bound diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c index 692f4053f08b..c2c10bbe24d6 100644 --- a/drivers/thermal/fair_share.c +++ b/drivers/thermal/fair_share.c @@ -59,13 +59,13 @@ static int get_trip_level(struct thermal_zone_device *tz) } static long get_target_state(struct thermal_zone_device *tz, - struct thermal_cooling_device *cdev, int weight, int level) + struct thermal_cooling_device *cdev, int percentage, int level) { unsigned long max_state; cdev->ops->get_max_state(cdev, &max_state); - return (long)(weight * level * max_state) / (100 * tz->trips); + return (long)(percentage * level * max_state) / (100 * tz->trips); } /** @@ -77,7 +77,7 @@ static long get_target_state(struct thermal_zone_device *tz, * * Parameters used for Throttling: * P1. max_state: Maximum throttle state exposed by the cooling device. - * P2. weight[i]/100: + * P2. percentage[i]/100: * How 'effective' the 'i'th device is, in cooling the given zone. * P3. cur_trip_level/max_no_of_trips: * This describes the extent to which the devices should be throttled. @@ -89,16 +89,32 @@ static long get_target_state(struct thermal_zone_device *tz, static int fair_share_throttle(struct thermal_zone_device *tz, int trip) { struct thermal_instance *instance; + int total_weight = 0; + int total_instance = 0; int cur_trip_level = get_trip_level(tz); list_for_each_entry(instance, &tz->thermal_instances, tz_node) { + if (instance->trip != trip) + continue; + + total_weight += instance->weight; + total_instance++; + } + + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { + int percentage; struct thermal_cooling_device *cdev = instance->cdev; if (instance->trip != trip) continue; - instance->target = get_target_state(tz, cdev, - instance->weight, cur_trip_level); + if (!total_weight) + percentage = 100 / total_instance; + else + percentage = (instance->weight * 100) / total_weight; + + instance->target = get_target_state(tz, cdev, percentage, + cur_trip_level); instance->cdev->updated = false; thermal_cdev_update(cdev); diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 00dacd4dfdce..bac0f52c7a1e 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -217,9 +217,12 @@ struct thermal_bind_params { /* * This is a measure of 'how effectively these devices can - * cool 'this' thermal zone. The shall be determined by platform - * characterization. This is on a 'percentage' scale. - * See Documentation/thermal/sysfs-api.txt for more information. + * cool 'this' thermal zone. It shall be determined by + * platform characterization. This value is relative to the + * rest of the weights so a cooling device whose weight is + * double that of another cooling device is twice as + * effective. See Documentation/thermal/sysfs-api.txt for more + * information. */ int weight; |