2019-05-27 09:55:15 +03:00
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// SPDX-License-Identifier: GPL-2.0-only
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2012-09-21 10:36:04 +04:00
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/*
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* step_wise.c - A step-by-step Thermal throttling governor
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*
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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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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/thermal.h>
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2022-06-29 18:10:11 +03:00
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#include <linux/minmax.h>
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2014-07-29 14:50:50 +04:00
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#include <trace/events/thermal.h>
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2012-09-21 10:36:04 +04:00
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#include "thermal_core.h"
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/*
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* If the temperature is higher than a trip point,
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* a. if the trend is THERMAL_TREND_RAISING, use higher cooling
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* state for this trip point
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thermal/drivers/step_wise: Fix temperature regulation misbehavior
There is a particular situation when the cooling device is cpufreq and the heat
dissipation is not efficient enough where the temperature increases little by
little until reaching the critical threshold and leading to a SoC reset.
The behavior is reproducible on a hikey6220 with bad heat dissipation (eg.
stacked with other boards).
Running a simple C program doing while(1); for each CPU of the SoC makes the
temperature to reach the passive regulation trip point and ends up to the
maximum allowed temperature followed by a reset.
This issue has been also reported by running the libhugetlbfs test suite.
What is observed is a ping pong between two cpu frequencies, 1.2GHz and 900MHz
while the temperature continues to grow.
It appears the step wise governor calls get_target_state() the first time with
the throttle set to true and the trend to 'raising'. The code selects logically
the next state, so the cpu frequency decreases from 1.2GHz to 900MHz, so far so
good. The temperature decreases immediately but still stays greater than the
trip point, then get_target_state() is called again, this time with the
throttle set to true *and* the trend to 'dropping'. From there the algorithm
assumes we have to step down the state and the cpu frequency jumps back to
1.2GHz. But the temperature is still higher than the trip point, so
get_target_state() is called with throttle=1 and trend='raising' again, we jump
to 900MHz, then get_target_state() is called with throttle=1 and
trend='dropping', we jump to 1.2GHz, etc ... but the temperature does not
stabilizes and continues to increase.
[ 237.922654] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 237.922678] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 237.922690] thermal cooling_device0: cur_state=0
[ 237.922701] thermal cooling_device0: old_target=0, target=1
[ 238.026656] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 238.026680] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 238.026694] thermal cooling_device0: cur_state=1
[ 238.026707] thermal cooling_device0: old_target=1, target=0
[ 238.134647] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 238.134667] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 238.134679] thermal cooling_device0: cur_state=0
[ 238.134690] thermal cooling_device0: old_target=0, target=1
In this situation the temperature continues to increase while the trend is
oscillating between 'dropping' and 'raising'. We need to keep the current state
untouched if the throttle is set, so the temperature can decrease or a higher
state could be selected, thus preventing this oscillation.
Keeping the next_target untouched when 'throttle' is true at 'dropping' time
fixes the issue.
The following traces show the governor does not change the next state if
trend==2 (dropping) and throttle==1.
[ 2306.127987] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2306.128009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2306.128021] thermal cooling_device0: cur_state=0
[ 2306.128031] thermal cooling_device0: old_target=0, target=1
[ 2306.231991] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.232016] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 2306.232030] thermal cooling_device0: cur_state=1
[ 2306.232042] thermal cooling_device0: old_target=1, target=1
[ 2306.335982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2306.336006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=1
[ 2306.336021] thermal cooling_device0: cur_state=1
[ 2306.336034] thermal cooling_device0: old_target=1, target=1
[ 2306.439984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.440008] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2306.440022] thermal cooling_device0: cur_state=1
[ 2306.440034] thermal cooling_device0: old_target=1, target=0
[ ... ]
After a while, if the temperature continues to increase, the next state becomes
2 which is 720MHz on the hikey. That results in the temperature stabilizing
around the trip point.
[ 2455.831982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2455.832006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=0
[ 2455.832019] thermal cooling_device0: cur_state=1
[ 2455.832032] thermal cooling_device0: old_target=1, target=1
[ 2455.935985] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2455.936013] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2455.936027] thermal cooling_device0: cur_state=1
[ 2455.936040] thermal cooling_device0: old_target=1, target=1
[ 2456.043984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2456.044009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2456.044023] thermal cooling_device0: cur_state=1
[ 2456.044036] thermal cooling_device0: old_target=1, target=1
[ 2456.148001] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2456.148028] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2456.148042] thermal cooling_device0: cur_state=1
[ 2456.148055] thermal cooling_device0: old_target=1, target=2
[ 2456.252009] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2456.252041] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2456.252058] thermal cooling_device0: cur_state=2
[ 2456.252075] thermal cooling_device0: old_target=2, target=1
IOW, this change is needed to keep the state for a cooling device if the
temperature trend is oscillating while the temperature increases slightly.
Without this change, the situation above leads to a catastrophic crash by a
hardware reset on hikey. This issue has been reported to happen on an OMAP
dra7xx also.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Keerthy <j-keerthy@ti.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-10-19 20:05:58 +03:00
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* b. if the trend is THERMAL_TREND_DROPPING, do nothing
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2012-11-19 12:10:20 +04:00
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* c. if the trend is THERMAL_TREND_RAISE_FULL, use upper limit
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* for this trip point
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* d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit
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* for this trip point
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* If the temperature is lower than a trip point,
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* a. if the trend is THERMAL_TREND_RAISING, do nothing
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* b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
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* state for this trip point, if the cooling state already
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* equals lower limit, deactivate the thermal instance
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* c. if the trend is THERMAL_TREND_RAISE_FULL, do nothing
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* d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit,
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* if the cooling state already equals lower limit,
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2015-01-29 20:57:21 +03:00
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* deactivate the thermal instance
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2012-09-21 10:36:04 +04:00
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*/
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static unsigned long get_target_state(struct thermal_instance *instance,
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2012-11-19 12:10:20 +04:00
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enum thermal_trend trend, bool throttle)
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2012-09-21 10:36:04 +04:00
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{
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struct thermal_cooling_device *cdev = instance->cdev;
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unsigned long cur_state;
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2013-06-17 17:24:24 +04:00
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unsigned long next_target;
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2012-09-21 10:36:04 +04:00
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2013-06-17 17:24:24 +04:00
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/*
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* We keep this instance the way it is by default.
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* Otherwise, we use the current state of the
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* cdev in use to determine the next_target.
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*/
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2012-09-21 10:36:04 +04:00
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cdev->ops->get_cur_state(cdev, &cur_state);
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2013-06-17 17:24:24 +04:00
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next_target = instance->target;
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thermal: debug: add debug statement for core and step_wise
To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.
Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671
A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:
[ 355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[ 355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[ 355.147644] get_target_state: thermal cooling_device8: cur_state=0
[ 355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[ 355.147652] get_target_state: thermal cooling_device7: cur_state=0
[ 355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[ 355.147660] get_target_state: thermal cooling_device6: cur_state=0
[ 355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[ 355.147668] get_target_state: thermal cooling_device5: cur_state=0
[ 355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[ 355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[ 355.147776] get_target_state: thermal cooling_device0: cur_state=0
[ 355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[ 355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[ 355.147845] get_target_state: thermal cooling_device1: cur_state=0
[ 355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[ 355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[ 355.147904] get_target_state: thermal cooling_device2: cur_state=0
[ 355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[ 355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[ 355.147963] get_target_state: thermal cooling_device3: cur_state=0
[ 355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[ 355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[ 355.148022] get_target_state: thermal cooling_device4: cur_state=0
[ 355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[ 355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[ 355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-12-02 09:54:26 +04:00
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dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
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2012-09-21 10:36:04 +04:00
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2015-10-30 11:31:47 +03:00
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if (!instance->initialized) {
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if (throttle) {
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2022-06-29 18:10:11 +03:00
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next_target = clamp((cur_state + 1), instance->lower, instance->upper);
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2015-10-30 11:31:47 +03:00
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} else {
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next_target = THERMAL_NO_TARGET;
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}
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return next_target;
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}
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2012-11-19 12:10:20 +04:00
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switch (trend) {
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case THERMAL_TREND_RAISING:
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2013-04-10 01:59:47 +04:00
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if (throttle) {
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2022-06-29 18:10:11 +03:00
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next_target = clamp((cur_state + 1), instance->lower, instance->upper);
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2013-04-10 01:59:47 +04:00
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}
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2012-11-19 12:10:20 +04:00
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break;
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case THERMAL_TREND_DROPPING:
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2014-09-24 12:27:10 +04:00
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if (cur_state <= instance->lower) {
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2012-11-19 12:10:20 +04:00
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if (!throttle)
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2013-06-17 17:24:24 +04:00
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next_target = THERMAL_NO_TARGET;
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2013-04-10 01:59:47 +04:00
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} else {
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thermal/drivers/step_wise: Fix temperature regulation misbehavior
There is a particular situation when the cooling device is cpufreq and the heat
dissipation is not efficient enough where the temperature increases little by
little until reaching the critical threshold and leading to a SoC reset.
The behavior is reproducible on a hikey6220 with bad heat dissipation (eg.
stacked with other boards).
Running a simple C program doing while(1); for each CPU of the SoC makes the
temperature to reach the passive regulation trip point and ends up to the
maximum allowed temperature followed by a reset.
This issue has been also reported by running the libhugetlbfs test suite.
What is observed is a ping pong between two cpu frequencies, 1.2GHz and 900MHz
while the temperature continues to grow.
It appears the step wise governor calls get_target_state() the first time with
the throttle set to true and the trend to 'raising'. The code selects logically
the next state, so the cpu frequency decreases from 1.2GHz to 900MHz, so far so
good. The temperature decreases immediately but still stays greater than the
trip point, then get_target_state() is called again, this time with the
throttle set to true *and* the trend to 'dropping'. From there the algorithm
assumes we have to step down the state and the cpu frequency jumps back to
1.2GHz. But the temperature is still higher than the trip point, so
get_target_state() is called with throttle=1 and trend='raising' again, we jump
to 900MHz, then get_target_state() is called with throttle=1 and
trend='dropping', we jump to 1.2GHz, etc ... but the temperature does not
stabilizes and continues to increase.
[ 237.922654] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 237.922678] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 237.922690] thermal cooling_device0: cur_state=0
[ 237.922701] thermal cooling_device0: old_target=0, target=1
[ 238.026656] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 238.026680] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 238.026694] thermal cooling_device0: cur_state=1
[ 238.026707] thermal cooling_device0: old_target=1, target=0
[ 238.134647] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 238.134667] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 238.134679] thermal cooling_device0: cur_state=0
[ 238.134690] thermal cooling_device0: old_target=0, target=1
In this situation the temperature continues to increase while the trend is
oscillating between 'dropping' and 'raising'. We need to keep the current state
untouched if the throttle is set, so the temperature can decrease or a higher
state could be selected, thus preventing this oscillation.
Keeping the next_target untouched when 'throttle' is true at 'dropping' time
fixes the issue.
The following traces show the governor does not change the next state if
trend==2 (dropping) and throttle==1.
[ 2306.127987] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2306.128009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2306.128021] thermal cooling_device0: cur_state=0
[ 2306.128031] thermal cooling_device0: old_target=0, target=1
[ 2306.231991] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.232016] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 2306.232030] thermal cooling_device0: cur_state=1
[ 2306.232042] thermal cooling_device0: old_target=1, target=1
[ 2306.335982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2306.336006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=1
[ 2306.336021] thermal cooling_device0: cur_state=1
[ 2306.336034] thermal cooling_device0: old_target=1, target=1
[ 2306.439984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.440008] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2306.440022] thermal cooling_device0: cur_state=1
[ 2306.440034] thermal cooling_device0: old_target=1, target=0
[ ... ]
After a while, if the temperature continues to increase, the next state becomes
2 which is 720MHz on the hikey. That results in the temperature stabilizing
around the trip point.
[ 2455.831982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2455.832006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=0
[ 2455.832019] thermal cooling_device0: cur_state=1
[ 2455.832032] thermal cooling_device0: old_target=1, target=1
[ 2455.935985] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2455.936013] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2455.936027] thermal cooling_device0: cur_state=1
[ 2455.936040] thermal cooling_device0: old_target=1, target=1
[ 2456.043984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2456.044009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2456.044023] thermal cooling_device0: cur_state=1
[ 2456.044036] thermal cooling_device0: old_target=1, target=1
[ 2456.148001] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2456.148028] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2456.148042] thermal cooling_device0: cur_state=1
[ 2456.148055] thermal cooling_device0: old_target=1, target=2
[ 2456.252009] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2456.252041] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2456.252058] thermal cooling_device0: cur_state=2
[ 2456.252075] thermal cooling_device0: old_target=2, target=1
IOW, this change is needed to keep the state for a cooling device if the
temperature trend is oscillating while the temperature increases slightly.
Without this change, the situation above leads to a catastrophic crash by a
hardware reset on hikey. This issue has been reported to happen on an OMAP
dra7xx also.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Keerthy <j-keerthy@ti.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-10-19 20:05:58 +03:00
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if (!throttle) {
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2022-06-29 18:10:11 +03:00
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next_target = clamp((cur_state - 1), instance->lower, instance->upper);
|
thermal/drivers/step_wise: Fix temperature regulation misbehavior
There is a particular situation when the cooling device is cpufreq and the heat
dissipation is not efficient enough where the temperature increases little by
little until reaching the critical threshold and leading to a SoC reset.
The behavior is reproducible on a hikey6220 with bad heat dissipation (eg.
stacked with other boards).
Running a simple C program doing while(1); for each CPU of the SoC makes the
temperature to reach the passive regulation trip point and ends up to the
maximum allowed temperature followed by a reset.
This issue has been also reported by running the libhugetlbfs test suite.
What is observed is a ping pong between two cpu frequencies, 1.2GHz and 900MHz
while the temperature continues to grow.
It appears the step wise governor calls get_target_state() the first time with
the throttle set to true and the trend to 'raising'. The code selects logically
the next state, so the cpu frequency decreases from 1.2GHz to 900MHz, so far so
good. The temperature decreases immediately but still stays greater than the
trip point, then get_target_state() is called again, this time with the
throttle set to true *and* the trend to 'dropping'. From there the algorithm
assumes we have to step down the state and the cpu frequency jumps back to
1.2GHz. But the temperature is still higher than the trip point, so
get_target_state() is called with throttle=1 and trend='raising' again, we jump
to 900MHz, then get_target_state() is called with throttle=1 and
trend='dropping', we jump to 1.2GHz, etc ... but the temperature does not
stabilizes and continues to increase.
[ 237.922654] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 237.922678] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 237.922690] thermal cooling_device0: cur_state=0
[ 237.922701] thermal cooling_device0: old_target=0, target=1
[ 238.026656] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 238.026680] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 238.026694] thermal cooling_device0: cur_state=1
[ 238.026707] thermal cooling_device0: old_target=1, target=0
[ 238.134647] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 238.134667] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 238.134679] thermal cooling_device0: cur_state=0
[ 238.134690] thermal cooling_device0: old_target=0, target=1
In this situation the temperature continues to increase while the trend is
oscillating between 'dropping' and 'raising'. We need to keep the current state
untouched if the throttle is set, so the temperature can decrease or a higher
state could be selected, thus preventing this oscillation.
Keeping the next_target untouched when 'throttle' is true at 'dropping' time
fixes the issue.
The following traces show the governor does not change the next state if
trend==2 (dropping) and throttle==1.
[ 2306.127987] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2306.128009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2306.128021] thermal cooling_device0: cur_state=0
[ 2306.128031] thermal cooling_device0: old_target=0, target=1
[ 2306.231991] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.232016] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=1
[ 2306.232030] thermal cooling_device0: cur_state=1
[ 2306.232042] thermal cooling_device0: old_target=1, target=1
[ 2306.335982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2306.336006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=1
[ 2306.336021] thermal cooling_device0: cur_state=1
[ 2306.336034] thermal cooling_device0: old_target=1, target=1
[ 2306.439984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2306.440008] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2306.440022] thermal cooling_device0: cur_state=1
[ 2306.440034] thermal cooling_device0: old_target=1, target=0
[ ... ]
After a while, if the temperature continues to increase, the next state becomes
2 which is 720MHz on the hikey. That results in the temperature stabilizing
around the trip point.
[ 2455.831982] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2455.832006] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=0
[ 2455.832019] thermal cooling_device0: cur_state=1
[ 2455.832032] thermal cooling_device0: old_target=1, target=1
[ 2455.935985] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2455.936013] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2455.936027] thermal cooling_device0: cur_state=1
[ 2455.936040] thermal cooling_device0: old_target=1, target=1
[ 2456.043984] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=0,throttle=1
[ 2456.044009] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=0,throttle=0
[ 2456.044023] thermal cooling_device0: cur_state=1
[ 2456.044036] thermal cooling_device0: old_target=1, target=1
[ 2456.148001] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=1,throttle=1
[ 2456.148028] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=1,throttle=1
[ 2456.148042] thermal cooling_device0: cur_state=1
[ 2456.148055] thermal cooling_device0: old_target=1, target=2
[ 2456.252009] thermal thermal_zone0: Trip0[type=1,temp=65000]:trend=2,throttle=1
[ 2456.252041] thermal thermal_zone0: Trip1[type=1,temp=75000]:trend=2,throttle=0
[ 2456.252058] thermal cooling_device0: cur_state=2
[ 2456.252075] thermal cooling_device0: old_target=2, target=1
IOW, this change is needed to keep the state for a cooling device if the
temperature trend is oscillating while the temperature increases slightly.
Without this change, the situation above leads to a catastrophic crash by a
hardware reset on hikey. This issue has been reported to happen on an OMAP
dra7xx also.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Keerthy <j-keerthy@ti.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-10-19 20:05:58 +03:00
|
|
|
}
|
2013-04-10 01:59:47 +04:00
|
|
|
}
|
2012-11-19 12:10:20 +04:00
|
|
|
break;
|
|
|
|
default:
|
|
|
|
break;
|
2012-09-21 10:36:04 +04:00
|
|
|
}
|
|
|
|
|
2013-06-17 17:24:24 +04:00
|
|
|
return next_target;
|
2012-09-21 10:36:04 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
static void update_passive_instance(struct thermal_zone_device *tz,
|
|
|
|
enum thermal_trip_type type, int value)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* If value is +1, activate a passive instance.
|
|
|
|
* If value is -1, deactivate a passive instance.
|
|
|
|
*/
|
thermal/core: Remove the 'forced_passive' option
The code was reorganized in 2012 with the commit 0c01ebbfd3caf1.
The main change is a loop on the trip points array and a unconditional
call to the throttle() ops of the governors for each of them even if
the trip temperature is not reached yet.
With this change, the 'forced_passive' is no longer checked in the
thermal_zone_device_update() function but in the step wise governor's
throttle() callback.
As the force_passive does no belong to the trip point array, the
thermal_zone_device_update() can not compare with the specified
passive temperature, thus does not detect the passive limit has been
crossed. Consequently, throttle() is never called and the
'forced_passive' branch is unreached.
In addition, the default processor cooling device is not automatically
bound to the thermal zone if there is not passive trip point, thus the
'forced_passive' can not operate.
If there is an active trip point, then the throttle function will be
called to mitigate at this temperature and the 'forced_passive' will
override the mitigation of the active trip point in this case but with
the default cooling device bound to the thermal zone, so usually a
fan, and that is not a passive cooling effect.
Given the regression exists since more than 8 years, nobody complained
and at the best of my knowledge there is no bug open in
https://bugzilla.kernel.org, it is reasonable to say it is unused.
Remove the 'forced_passive' related code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org
2020-12-15 02:38:04 +03:00
|
|
|
if (type == THERMAL_TRIP_PASSIVE)
|
2012-09-21 10:36:04 +04:00
|
|
|
tz->passive += value;
|
|
|
|
}
|
|
|
|
|
2022-10-03 12:25:37 +03:00
|
|
|
static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip_id)
|
2012-09-21 10:36:04 +04:00
|
|
|
{
|
|
|
|
enum thermal_trend trend;
|
2012-11-22 11:45:02 +04:00
|
|
|
struct thermal_instance *instance;
|
2022-10-03 12:25:37 +03:00
|
|
|
struct thermal_trip trip;
|
2012-11-22 11:45:02 +04:00
|
|
|
bool throttle = false;
|
|
|
|
int old_target;
|
2012-09-21 10:36:04 +04:00
|
|
|
|
2022-10-03 12:25:37 +03:00
|
|
|
__thermal_zone_get_trip(tz, trip_id, &trip);
|
2012-09-21 10:36:04 +04:00
|
|
|
|
2022-10-03 12:25:37 +03:00
|
|
|
trend = get_tz_trend(tz, trip_id);
|
2012-09-21 10:36:04 +04:00
|
|
|
|
2022-10-03 12:25:37 +03:00
|
|
|
if (tz->temperature >= trip.temperature) {
|
2012-11-22 11:45:02 +04:00
|
|
|
throttle = true;
|
2022-10-03 12:25:37 +03:00
|
|
|
trace_thermal_zone_trip(tz, trip_id, trip.type);
|
2014-07-29 14:50:50 +04:00
|
|
|
}
|
2012-11-22 11:45:02 +04:00
|
|
|
|
2015-07-24 09:12:54 +03:00
|
|
|
dev_dbg(&tz->device, "Trip%d[type=%d,temp=%d]:trend=%d,throttle=%d\n",
|
2022-10-03 12:25:37 +03:00
|
|
|
trip_id, trip.type, trip.temperature, trend, throttle);
|
thermal: debug: add debug statement for core and step_wise
To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.
Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671
A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:
[ 355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[ 355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[ 355.147644] get_target_state: thermal cooling_device8: cur_state=0
[ 355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[ 355.147652] get_target_state: thermal cooling_device7: cur_state=0
[ 355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[ 355.147660] get_target_state: thermal cooling_device6: cur_state=0
[ 355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[ 355.147668] get_target_state: thermal cooling_device5: cur_state=0
[ 355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[ 355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[ 355.147776] get_target_state: thermal cooling_device0: cur_state=0
[ 355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[ 355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[ 355.147845] get_target_state: thermal cooling_device1: cur_state=0
[ 355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[ 355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[ 355.147904] get_target_state: thermal cooling_device2: cur_state=0
[ 355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[ 355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[ 355.147963] get_target_state: thermal cooling_device3: cur_state=0
[ 355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[ 355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[ 355.148022] get_target_state: thermal cooling_device4: cur_state=0
[ 355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[ 355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[ 355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-12-02 09:54:26 +04:00
|
|
|
|
2012-11-22 11:45:02 +04:00
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
2022-10-03 12:25:37 +03:00
|
|
|
if (instance->trip != trip_id)
|
2012-11-22 11:45:02 +04:00
|
|
|
continue;
|
|
|
|
|
|
|
|
old_target = instance->target;
|
|
|
|
instance->target = get_target_state(instance, trend, throttle);
|
thermal: debug: add debug statement for core and step_wise
To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.
Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671
A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:
[ 355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[ 355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[ 355.147644] get_target_state: thermal cooling_device8: cur_state=0
[ 355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[ 355.147652] get_target_state: thermal cooling_device7: cur_state=0
[ 355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[ 355.147660] get_target_state: thermal cooling_device6: cur_state=0
[ 355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[ 355.147668] get_target_state: thermal cooling_device5: cur_state=0
[ 355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[ 355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[ 355.147776] get_target_state: thermal cooling_device0: cur_state=0
[ 355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[ 355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[ 355.147845] get_target_state: thermal cooling_device1: cur_state=0
[ 355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[ 355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[ 355.147904] get_target_state: thermal cooling_device2: cur_state=0
[ 355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[ 355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[ 355.147963] get_target_state: thermal cooling_device3: cur_state=0
[ 355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[ 355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[ 355.148022] get_target_state: thermal cooling_device4: cur_state=0
[ 355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[ 355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[ 355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-12-02 09:54:26 +04:00
|
|
|
dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
|
|
|
|
old_target, (int)instance->target);
|
2012-11-22 11:45:02 +04:00
|
|
|
|
2015-10-30 11:31:47 +03:00
|
|
|
if (instance->initialized && old_target == instance->target)
|
2013-06-17 17:24:23 +04:00
|
|
|
continue;
|
|
|
|
|
2012-11-22 11:45:02 +04:00
|
|
|
/* Activate a passive thermal instance */
|
|
|
|
if (old_target == THERMAL_NO_TARGET &&
|
|
|
|
instance->target != THERMAL_NO_TARGET)
|
2022-10-03 12:25:37 +03:00
|
|
|
update_passive_instance(tz, trip.type, 1);
|
2012-11-22 11:45:02 +04:00
|
|
|
/* Deactivate a passive thermal instance */
|
|
|
|
else if (old_target != THERMAL_NO_TARGET &&
|
|
|
|
instance->target == THERMAL_NO_TARGET)
|
2022-10-03 12:25:37 +03:00
|
|
|
update_passive_instance(tz, trip.type, -1);
|
2012-11-22 11:45:02 +04:00
|
|
|
|
2015-10-30 11:31:47 +03:00
|
|
|
instance->initialized = true;
|
thermal: fix race condition when updating cooling device
When multiple thermal zones are bound to the same cooling device, multiple
kernel threads may want to update the cooling device state by calling
thermal_cdev_update(). Having cdev not protected by a mutex can lead to a race
condition. Consider the following situation with two kernel threads k1 and k2:
Thread k1 Thread k2
||
|| call thermal_cdev_update()
|| ...
|| set_cur_state(cdev, target);
call power_actor_set_power() ||
... ||
instance->target = state; ||
cdev->updated = false; ||
|| cdev->updated = true;
|| // completes execution
call thermal_cdev_update() ||
// cdev->updated == true ||
return; ||
\/
time
k2 has already looped through the thermal instances looking for the deepest
cooling device state and is preempted right before setting cdev->updated to
true. Now, k1 runs, modifies the thermal instance state and sets cdev->updated
to false. Then, k1 is preempted and k2 continues the execution by setting
cdev->updated to true, therefore preventing k1 from performing the update.
Notice that this is not an issue if k2 looks at the instance->target modified by
k1 "after" it is assigned by k1. In fact, in this case the update will happen
anyway and k1 can safely return immediately from thermal_cdev_update().
This may lead to a situation where a thermal governor never updates the cooling
device. For example, this is the case for the step_wise governor: when calling
the function thermal_zone_trip_update(), the governor may always get a new state
equal to the old one (which, however, wasn't notified to the cooling device) and
will therefore skip the update.
CC: Zhang Rui <rui.zhang@intel.com>
CC: Eduardo Valentin <edubezval@gmail.com>
CC: Peter Feuerer <peter@piie.net>
Reported-by: Toby Huang <toby.huang@arm.com>
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-06-02 17:25:31 +03:00
|
|
|
mutex_lock(&instance->cdev->lock);
|
2012-11-22 11:45:02 +04:00
|
|
|
instance->cdev->updated = false; /* cdev needs update */
|
thermal: fix race condition when updating cooling device
When multiple thermal zones are bound to the same cooling device, multiple
kernel threads may want to update the cooling device state by calling
thermal_cdev_update(). Having cdev not protected by a mutex can lead to a race
condition. Consider the following situation with two kernel threads k1 and k2:
Thread k1 Thread k2
||
|| call thermal_cdev_update()
|| ...
|| set_cur_state(cdev, target);
call power_actor_set_power() ||
... ||
instance->target = state; ||
cdev->updated = false; ||
|| cdev->updated = true;
|| // completes execution
call thermal_cdev_update() ||
// cdev->updated == true ||
return; ||
\/
time
k2 has already looped through the thermal instances looking for the deepest
cooling device state and is preempted right before setting cdev->updated to
true. Now, k1 runs, modifies the thermal instance state and sets cdev->updated
to false. Then, k1 is preempted and k2 continues the execution by setting
cdev->updated to true, therefore preventing k1 from performing the update.
Notice that this is not an issue if k2 looks at the instance->target modified by
k1 "after" it is assigned by k1. In fact, in this case the update will happen
anyway and k1 can safely return immediately from thermal_cdev_update().
This may lead to a situation where a thermal governor never updates the cooling
device. For example, this is the case for the step_wise governor: when calling
the function thermal_zone_trip_update(), the governor may always get a new state
equal to the old one (which, however, wasn't notified to the cooling device) and
will therefore skip the update.
CC: Zhang Rui <rui.zhang@intel.com>
CC: Eduardo Valentin <edubezval@gmail.com>
CC: Peter Feuerer <peter@piie.net>
Reported-by: Toby Huang <toby.huang@arm.com>
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-06-02 17:25:31 +03:00
|
|
|
mutex_unlock(&instance->cdev->lock);
|
2012-11-22 11:45:02 +04:00
|
|
|
}
|
2012-09-21 10:36:04 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2015-01-29 20:57:21 +03:00
|
|
|
* step_wise_throttle - throttles devices associated with the given zone
|
2019-11-20 18:45:12 +03:00
|
|
|
* @tz: thermal_zone_device
|
|
|
|
* @trip: trip point index
|
2012-09-21 10:36:04 +04:00
|
|
|
*
|
|
|
|
* Throttling Logic: This uses the trend of the thermal zone to throttle.
|
|
|
|
* If the thermal zone is 'heating up' this throttles all the cooling
|
|
|
|
* devices associated with the zone and its particular trip point, by one
|
|
|
|
* step. If the zone is 'cooling down' it brings back the performance of
|
|
|
|
* the devices by one step.
|
|
|
|
*/
|
2012-09-27 14:58:12 +04:00
|
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static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
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2012-09-21 10:36:04 +04:00
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{
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struct thermal_instance *instance;
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2022-08-05 18:38:33 +03:00
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lockdep_assert_held(&tz->lock);
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2012-09-21 10:36:04 +04:00
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2022-08-05 18:38:32 +03:00
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thermal_zone_trip_update(tz, trip);
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2012-09-21 10:36:04 +04:00
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list_for_each_entry(instance, &tz->thermal_instances, tz_node)
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thermal_cdev_update(instance->cdev);
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return 0;
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}
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2012-09-27 14:58:12 +04:00
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static struct thermal_governor thermal_gov_step_wise = {
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2012-12-12 11:31:37 +04:00
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.name = "step_wise",
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2012-09-21 10:36:04 +04:00
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.throttle = step_wise_throttle,
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};
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2019-06-12 23:13:25 +03:00
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THERMAL_GOVERNOR_DECLARE(thermal_gov_step_wise);
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