mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-24 10:49:54 +02:00
Rafael J. Wysocki
19cd2dc4d4
[ Upstream commit0dc23567c2] In almost all places where a thermal zone's list of thermal instances is walked, there is a check to match a specific trip point and it is walked in vain whenever there are no cooling devices associated with the given trip. To address this, store the lists of thermal instances in trip point descriptors instead of storing them in thermal zones and adjust all code using those lists accordingly. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/5522726.Sb9uPGUboI@rjwysocki.net Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Stable-dep-of:0cde378a10("thermal: gov_power_allocator: Update total_weight on bind and cdev updates") Signed-off-by: Sasha Levin <sashal@kernel.org>
133 lines
3.9 KiB
C
133 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* gov_bang_bang.c - A simple thermal throttling governor using hysteresis
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*
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* Copyright (C) 2014 Peter Kaestle <peter@piie.net>
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*
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* Based on step_wise.c with following Copyrights:
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* Copyright (C) 2012 Intel Corp
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* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
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*/
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#include <linux/thermal.h>
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#include "thermal_core.h"
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static void bang_bang_set_instance_target(struct thermal_instance *instance,
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unsigned int target)
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{
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if (instance->target != 0 && instance->target != 1 &&
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instance->target != THERMAL_NO_TARGET)
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pr_debug("Unexpected state %ld of thermal instance %s in bang-bang\n",
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instance->target, instance->name);
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/*
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* Enable the fan when the trip is crossed on the way up and disable it
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* when the trip is crossed on the way down.
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*/
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instance->target = target;
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instance->initialized = true;
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dev_dbg(&instance->cdev->device, "target=%ld\n", instance->target);
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mutex_lock(&instance->cdev->lock);
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__thermal_cdev_update(instance->cdev);
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mutex_unlock(&instance->cdev->lock);
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}
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/**
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* bang_bang_control - controls devices associated with the given zone
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* @tz: thermal_zone_device
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* @trip: the trip point
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* @crossed_up: whether or not the trip has been crossed on the way up
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*
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* Regulation Logic: a two point regulation, deliver cooling state depending
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* on the previous state shown in this diagram:
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*
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* Fan: OFF ON
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*
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* |
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* |
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* trip_temp: +---->+
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* | | ^
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* | | |
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* | | Temperature
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* (trip_temp - hyst): +<----+
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* |
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* |
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* |
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*
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* * If the fan is not running and temperature exceeds trip_temp, the fan
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* gets turned on.
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* * In case the fan is running, temperature must fall below
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* (trip_temp - hyst) so that the fan gets turned off again.
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*
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*/
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static void bang_bang_control(struct thermal_zone_device *tz,
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const struct thermal_trip *trip,
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bool crossed_up)
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{
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const struct thermal_trip_desc *td = trip_to_trip_desc(trip);
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struct thermal_instance *instance;
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lockdep_assert_held(&tz->lock);
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dev_dbg(&tz->device, "Trip%d[temp=%d]:temp=%d:hyst=%d\n",
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thermal_zone_trip_id(tz, trip), trip->temperature,
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tz->temperature, trip->hysteresis);
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list_for_each_entry(instance, &td->thermal_instances, trip_node)
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bang_bang_set_instance_target(instance, crossed_up);
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}
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static void bang_bang_manage(struct thermal_zone_device *tz)
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{
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const struct thermal_trip_desc *td;
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struct thermal_instance *instance;
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/* If the code below has run already, nothing needs to be done. */
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if (tz->governor_data)
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return;
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for_each_trip_desc(tz, td) {
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const struct thermal_trip *trip = &td->trip;
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bool turn_on;
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if (trip->temperature == THERMAL_TEMP_INVALID ||
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trip->type == THERMAL_TRIP_CRITICAL ||
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trip->type == THERMAL_TRIP_HOT)
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continue;
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/*
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* Adjust the target states for uninitialized thermal instances
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* to the thermal zone temperature and the trip point threshold.
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*/
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turn_on = tz->temperature >= td->threshold;
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list_for_each_entry(instance, &td->thermal_instances, trip_node) {
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if (!instance->initialized)
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bang_bang_set_instance_target(instance, turn_on);
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}
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}
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tz->governor_data = (void *)true;
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}
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static void bang_bang_update_tz(struct thermal_zone_device *tz,
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enum thermal_notify_event reason)
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{
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/*
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* Let bang_bang_manage() know that it needs to walk trips after binding
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* a new cdev and after system resume.
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*/
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if (reason == THERMAL_TZ_BIND_CDEV || reason == THERMAL_TZ_RESUME)
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tz->governor_data = NULL;
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}
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static struct thermal_governor thermal_gov_bang_bang = {
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.name = "bang_bang",
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.trip_crossed = bang_bang_control,
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.manage = bang_bang_manage,
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.update_tz = bang_bang_update_tz,
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};
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THERMAL_GOVERNOR_DECLARE(thermal_gov_bang_bang);
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