Android Thermal HAL 降龍十八掌

二的次方發表於2021-11-12
Android

基本概念

參閱下面兩篇文章，就可以大概瞭解一些概念的內容了

https://source.android.com/devices/architecture/hidl/thermal-mitigation

https://blog.csdn.net/feelabclihu/article/details/107873407

 

功能實現

這裡我們不做講解，直接給參考例子，基本拿來可以用

》Thermal HAL 2.0的實現

https://github.com/LineageOS/android_hardware_google_pixel/tree/lineage-18.1/thermal

》sepolicy相關設定

https://github.com/LineageOS/android_hardware_google_pixel-sepolicy/tree/lineage-19.0/thermal

》thermal_info_config配置檔案,根據自身系統配置

https://github.com/LineageOS/android_device_google_taimen/blob/lineage-17.1/thermal_info_config.json

 

測試

技巧一：

執行 adb shell dumpsys thermalservice 可以檢視溫度的資訊，例如：

Android Thermal HAL 降龍十八掌

 

技巧二：

Linux kernel中有模擬溫度的方式，編核心時開啟選項開關CONFIG_THERMAL_EMULATION=y，這樣就會看到如下這個值：

/sys/class/thermal/thermal_zone0/emul_temp

之後測試可以：

echo  100000 > /sys/class/thermal/thermal_zone0/emul_temp

然後使用dumpsys thermalservice 檢視這個模擬的溫度值

 

VTS/CTS測試

幾個相關的測試項

run vts -m VtsHalThermalV2_0TargetTest

run vts -m VtsHalThermalV1_0TargetTest

run vts -m VtsHalThermalV1_1TargetTest

run cts -m CtsOsTestCases -t android.os.cts.PowerManager_ThermalTest

 

補充

/frameworks/base/services/core/java/com/android/server/power/ThermalManagerService.java

Android framework中有去註冊監聽器，檢測Thermal HAL 的回撥事件，高溫時可能出發shutdown

private void shutdownIfNeeded(Temperature temperature) {
        if (temperature.getStatus() != Temperature.THROTTLING_SHUTDOWN) {
            return;
        }

        final PowerManager powerManager = getContext().getSystemService(PowerManager.class);
        switch (temperature.getType()) {
            case Temperature.TYPE_CPU:
                // Fall through
            case Temperature.TYPE_GPU:
                // Fall through
            case Temperature.TYPE_NPU:
                // Fall through
            case Temperature.TYPE_SKIN:
                powerManager.shutdown(false, PowerManager.SHUTDOWN_THERMAL_STATE, false);
                break;
            case Temperature.TYPE_BATTERY:
                powerManager.shutdown(false, PowerManager.SHUTDOWN_BATTERY_THERMAL_STATE, false);
                break;
        }
    }

 

關於溫度的幾個等級可以參考 https://source.android.com/devices/architecture/hidl/thermal-mitigation

觸發這些事件的溫度就是我們在thermal_info_config.json配置的， 如果不需要觸發回撥事件可以設定 "Monitor":false

    "Sensors":[
        {
            "Name":"cpu-thermal",
            "Type":"CPU",
            "HotThreshold":[
                "NAN",
                "NAN",
                "NAN",
                95.0,
                "NAN",
                "NAN",
                125.0
            ],
            "VrThreshold":"NAN",
            "Multiplier":0.001,
            "Monitor":false
        }
    ]

 

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