| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "ThermalManager.h" |
| |
| #include "SkOSFile.h" |
| |
| #include <stdio.h> |
| |
| #ifdef THERMAL_MANAGER_SUPPORTED |
| |
| /* |
| * ThermalManager is completely dependent on sysfs to monitor thermal temperatures. In sysfs |
| * thermal management is controlled by a number of thermal zones. They are laid out as follows: |
| * /sys/class/thermal/thermal_zoneN where N is the number of the thermal zone starting at 0. |
| * |
| * Inside each thermal_zone folder is a file called 'temp,' which has the current temperature |
| * reading from the sensor in that zone, as well as 0 or more files called 'trip_point_N_temp.' |
| * |
| * When the reading in temp is greater than one of the numbers in the trip_point files, then the |
| * kernel will take some kind of action. This is all documented online. |
| * |
| * In any case, the goal of this class is to sleep right before a trip point is about to be |
| * triggered, thus naturally cooling the system and preventing thermal throttling. |
| */ |
| |
| ThermalManager::ThermalManager(int32_t threshold, uint32_t sleepIntervalMs, uint32_t timeoutMs) |
| : fSleepIntervalMs(sleepIntervalMs) |
| , fTimeoutMs(timeoutMs) { |
| static const char* kThermalZonePath = "/sys/class/thermal/"; |
| SkOSFile::Iter it(kThermalZonePath); |
| SkString path; |
| while (it.next(&path, true)) { |
| if (!path.contains("thermal_zone")) { |
| continue; |
| } |
| |
| SkString fullPath(kThermalZonePath); |
| fullPath.append(path); |
| SkOSFile::Iter thermalZoneIt(fullPath.c_str()); |
| |
| SkString filename; |
| while (thermalZoneIt.next(&filename)) { |
| if (!(filename.contains("trip_point") && filename.contains("temp"))) { |
| continue; |
| } |
| |
| fTripPoints.push_back(TripPoint(fullPath, filename, threshold)); |
| } |
| } |
| } |
| |
| bool ThermalManager::coolOffIfNecessary() { |
| uint32_t i = 0, totalTimeSleptMs = 0; |
| while (i < (uint32_t)fTripPoints.count() && totalTimeSleptMs < fTimeoutMs) { |
| if (fTripPoints[i].willTrip()) { |
| sleep(fSleepIntervalMs); |
| totalTimeSleptMs += fSleepIntervalMs; |
| } else { |
| i++; |
| } |
| } |
| |
| return totalTimeSleptMs < fTimeoutMs; |
| } |
| |
| int32_t ThermalManager::OpenFileAndReadInt32(const char* path) { |
| FILE* tempFile = fopen(path, "r"); |
| SkASSERT(tempFile); |
| int32_t value; |
| int ret = fscanf(tempFile, "%d", &value); |
| if (!ret) { |
| SkDebugf("Could not read temperature\n"); |
| SkASSERT(false); |
| } |
| |
| fclose(tempFile); |
| return value; |
| } |
| |
| ThermalManager::TripPoint::TripPoint(SkString thermalZoneRoot, SkString pointName, |
| int32_t threshold) |
| : fThermalZoneRoot(thermalZoneRoot) |
| , fPointName(pointName) { |
| SkString fullPath(thermalZoneRoot); |
| fullPath.appendf("/%s", pointName.c_str()); |
| fPoint = OpenFileAndReadInt32(fullPath.c_str()); |
| fBase = GetTemp(fThermalZoneRoot); |
| fDisabled = fBase >= fPoint + fThreshold; // We disable any trip point which start off |
| // triggered |
| fThreshold = threshold; |
| if (!fDisabled) { |
| SkDebugf("Trip point %s base - %d trip point-%d\n", fullPath.c_str(), |
| fBase, fPoint); |
| } |
| } |
| |
| bool ThermalManager::TripPoint::willTrip() { |
| int32_t currentTemp = GetTemp(fThermalZoneRoot); |
| bool wouldTrip = !fDisabled && currentTemp + fThreshold >= fPoint; |
| |
| if (wouldTrip) { |
| SkDebugf("%s/%s would trip {%d,%d,%d,%d}\n", fThermalZoneRoot.c_str(), |
| fPointName.c_str(), fBase, currentTemp, fPoint, fThreshold); |
| } |
| return wouldTrip; |
| } |
| |
| #endif |