thermal-conf.xml

thermal-conf.xml(5)           File Formats Manual          thermal-conf.xml(5)



NAME
       thermal-conf.xml - Configuration file for thermal daemon

SYNOPSIS
       $(TDCONFDIR)/etc/thermald/thermal-conf.xml


DESCRIPTION
       thermal-conf.xml is a configuration file for the thermal daemon. It is
       used to configure thermal sensors, zone and cooling devices.The
       location of this file depends on the configuration option used during
       build time.

       The terminology used in this file conforms to "Advanced Configuration
       and Power Interface Specification". The ACPI thermal model is based
       around conceptual platform regions called thermal zones that physically
       contain devices, thermal sensors, and cooling controls. For example of
       a thermal zone can be a CPU or a laptop cover. A zone can contain
       multiple sensors for monitoring temperature. A cooling device provides
       interface to reduce the temperature of a source device, which causes
       increase in the temperature. An example of a cooling device is a FAN or
       some Linux driver which can throttle the source device.

       A thermal zone configuration includes one or more trip points. A trip
       point is a temperature at which a cooling device needs to be activated.

       A cooling device can be either active or passive. An example of an
       active device is a FAN, which will not reduce performance at the cost
       of consuming more power and noise. A passive device uses performance
       throttling to control temperature. In addition to cooling devices
       present in the thermal sysfs, the following cooling devices are built
       into the thermald, which can be used as valid cooling device type:

                   - rapl_controller

                   - intel_pstate

                   - cpufreq

                   - LCD

       The thermal sysfs under Linux (/sys/class/thermal) provides a way to
       represent per platform ACPI configuration. The kernel thermal governor
       uses this data to keep the platform thermals under control. But there
       are some limitations, which thermald tries to resolve. For example:

       - If the ACPI data is not optimized or buggy. In this case thermal-
       conf.xml can be used to correct the behavior without change in BIOS.

              - There may be thermal zones exposed by the thermal sysfs
              without associated cooling actions. In this case thermal
              conf.xml can be used to tie the cooling devices to those zones.

              - The best cooling method may not be in the thermal sysfs. In
              this case thermal-conf.xml can be used to bind a zone to an
              external cooling device.

              - Specify thermal relationships. A zone can be influenced by
              multiple source devices with varying degrees. In this case
              thermal-conf.xml can be used to define the relative influence
              for apply compensation.


FILE FORMAT
       The configuration file format conforms to XML specifications. A set of
       tags defined to define platform, sensors, zones, cooling devices and
       trip points.

       <ThermalConfiguration>
         <Platform>
           <Name>Example Platform Name</Name>
           <!-- UUID is optional, if present this will be matched. Both product
                name and UUID can contain wild card "*", which matches any
                platform. -->
           <UUID>Example UUID</UUID>
           <!-- configuration file format conforms to XML specifications. A
                set of tags defined to define platform, sensors, zones, cooling
                devices and trip points. -->
           <ProductName>Example Product Name</ProductName>
           <Preference>QUIET|PERFORMANCE</Preference>
           <!-- Quiet mode will only use passive cooling device. "PERFORMANCE"
                will only select active devices. -->
           <ThermalSensors>
             <ThermalSensor>
               <!-- New Sensor with a type and path -->
               <Type>example_sensor_1</Type>
               <Path>/some_path</Path>
               <AsyncCapable>0</AsyncCapable>
             </ThermalSensor>
             <ThermalSensor>
               <!-- Already present in thermal sysfs, enable this or
                    add/change config For example, here we are indicating
                    that sensor can do async events to avoid polling. -->
               <Type>example_thermal_sysfs_sensor</Type>
               <!-- If async capable, then we don't need to poll. -->
               <AsyncCapable>1</AsyncCapable>
             </ThermalSensor>
           </ThermalSensors>
           <ThermalZones>
             <ThermalZone>
               <Type>Example Zone type</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>example_sensor_1</SensorType>
                   <!-- Temperature at which to take action. -->
                   <Temperature> 75000 </Temperature>
                   <!-- max/passive/active If a MAX type is specified, then
                        daemon will use PID control to aggressively throttle
                        to avoid reaching this temp. -->
                   <type>max</type>
                   <!-- SEQUENTIAL | PARALLEL. When a trip point temp is
                        violated, then number of cooling devices can be
                        activated. If control type is SEQUENTIAL then, it
                        will exhaust first cooling device
                        before trying next. -->
                   <ControlType>SEQUENTIAL</ControlType>
                   <CoolingDevice>
                     <index>1</index>
                     <type>example_cooling_device</type>
                     <!-- Influence will be used order cooling devices. First
                          cooling device will be used, which has highest
                          influence. -->
                     <influence> 100 </influence>
                     <!-- Delay in using this cdev, this takes some time too
                          actually cool a zone. -->
                     <SamplingPeriod> 12 </SamplingPeriod>
                     <!-- Set a specific state of this cooling device when this
                          trip is violated. -->
                     <TargetState> 6 </TargetState>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
           <CoolingDevices>
             <CoolingDevice>
               <!-- Cooling device can be specified by a type and optionally
                    a sysfs path. If the type is already present in thermal
                    sysfs, there is no need of a path. Compensation can use
                    min/max and step size to increasing cool the system.
                    Debounce period can be used to force a waiting period
                    for action. -->
               <Type>example_cooling_device</Type>
               <MinState>0</MinState>
               <IncDecStep>10</IncDecStep>
               <ReadBack> 0 </ReadBack>
               <MaxState>50</MaxState>
               <DebouncePeriod>5000</DebouncePeriod>
               <!-- If there are no PID parameters, compensation increase step
                    wise and exponentially (if single step is not able to
                    change trend).
                    Alternatively a PID parameters can be specified then next
                    step will use PID calculation using provided PID
                    constants. -->
               <PidControl>
                 <kp>0.001</kp>
                 <kd>0.0001</kd>
                 <ki>0.0001</ki>
               </PidControl>
               <!-- Write some prefix attached to state value, like below the
                    prefix is "level ". It will preserve spaces as entered
                    when writing to sysfs. -->
               <WritePrefix>level </WritePrefix>
             </CoolingDevice>
           </CoolingDevices>
         </Platform>
       </ThermalConfiguration>

EXAMPLE CONFIGURATIONS
       Example 1: This is a very simple configuration, to change the passive
       limit on the CPU. Instead of default, this new temperature 86C in the
       configuration is used. This will start cooling, once the temperature
       reaches 86C.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Override CPU default passive</Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>cpu</Type>
               <TripPoints>
                 <TripPoint>
                   <Temperature>86000</Temperature>
                   <type>passive</type>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
         </Platform>
       </ThermalConfiguration>

       Example 2: In this configuration, we are controlling backlight when
       some sensor "SEN2" reaches 60C. Here "LCD" is a standard cooling
       device, which uses Linux backlight sysfs interface. "LCD_Zone" is a
       valid thermal zone in Linux thermal sysfs on the test platform, hence
       we don't need to provide path for sysfs for "LCD_Zone". The Linux
       thermal sysfs is already parsed and loaded by thermald program.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Change Backlight</Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>LCD_Zone</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>SEN2</SensorType>
                   <Temperature>60000</Temperature>
                   <type>passive</type>
                   <CoolingDevice>
                     <Type>LCD</Type>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
         </Platform>
       </ThermalConfiguration>

       Example 3: In this example Lenovo Thinkpad X220 and fan speed is
       controlled. Here a cooling device "_Fan", can be controlled via sysfs
       /sys/devices/platform/thinkpad_hwmon/pwm1. When the x86_pkg_temp
       reaches 45C, Fan is started with increasing speeds, if the temperature
       can't be controlled at 45C.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Lenovo ThinkPad X220</Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>x86_pkg_temp</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>x86_pkg_temp</SensorType>
                   <Temperature>45000</Temperature>
                   <type>passive</type>
                   <ControlType>SEQUENTIAL</ControlType>
                   <CoolingDevice>
                     <index>1</index>
                     <type>_Fan</type>
                     <influence> 100 </influence>
                     <SamplingPeriod> 12 </SamplingPeriod>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
           <CoolingDevices>
             <CoolingDevice>
               <Type>_Fan</Type>
               <Path>/sys/devices/platform/thinkpad_hwmon/pwm1</Path>
               <MinState>0</MinState>
               <IncDecStep>30</IncDecStep>
               <ReadBack> 0 </ReadBack>
               <MaxState>255</MaxState>
               <DebouncePeriod>5</DebouncePeriod>
             </CoolingDevice>
           </CoolingDevices>
         </Platform>
       </ThermalConfiguration>

       Example 4: The following example shows how PID can be used. Here once
       temperature exceeds 80C, compensation is calculated using PID using 80C
       as set point of PID. The compensation depends on error from the set
       point. Here the default built in processor cooling device is used with
       min state as 0 and max state as 10.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Use PID param </Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>x86_pkg_temp</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>x86_pkg_temp</SensorType>
                   <Temperature>80000</Temperature>
                   <type>passive</type>
                   <ControlType>SEQUENTIAL</ControlType>
                   <CoolingDevice>
                     <type>Processor</type>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
           <CoolingDevices>
             <CoolingDevice>
               <Type>Processor</Type>
               <PidControl>
                 <kp>0.0002</kp>
                 <kd>0</kd>
                 <ki>0</ki>
               </PidControl>
             </CoolingDevice>
           </CoolingDevices>
         </Platform>
       </ThermalConfiguration>

       Example 5: The following example shows how to control Fan when the
       sysfs expects some string prefix. For example instead of just write a
       number to fan control sysfs, the interface requires "level " in front
       of the speed index value.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Use Fan control first then CPU throttle </Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>x86_pkg_temp</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>x86_pkg_temp</SensorType>
                   <Temperature>80000</Temperature>
                   <type>passive</type>
                   <ControlType>SEQUENTIAL</ControlType>
                   <CoolingDevice>
                     <type>_fan_</type>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
           <CoolingDevices>
             <CoolingDevice>
               <Type>_fan_</Type>
               <Path>/proc/acpi/ibm/fan</Path>
               <WritePrefix>level </WritePrefix>
               <MinState>0</MinState>
               <MaxState>5</MaxState>
               <DebouncePeriod>10</DebouncePeriod>
             </CoolingDevice>
           </CoolingDevices>
         </Platform>
       </ThermalConfiguration>

       Example 6: Similar to example 5, but write different speeds at
       different temperatures.

       <?xml version="1.0"?>
       <ThermalConfiguration>
         <Platform>
           <Name>Use Fan control first then CPU throttle </Name>
           <ProductName>*</ProductName>
           <Preference>QUIET</Preference>
           <ThermalZones>
             <ThermalZone>
               <Type>x86_pkg_temp</Type>
               <TripPoints>
                 <TripPoint>
                   <SensorType>x86_pkg_temp</SensorType>
                   <Temperature>80000</Temperature>
                   <type>passive</type>
                   <CoolingDevice>
                     <type>_fan_</type>
                     <TargetState>1</TargetState>
                   </CoolingDevice>
                 </TripPoint>
                 <TripPoint>
                   <SensorType>x86_pkg_temp</SensorType>
                   <Temperature>85000</Temperature>
                   <type>passive</type>
                   <CoolingDevice>
                     <type>_fan_</type>
                     <TargetState>2</TargetState>
                   </CoolingDevice>
                 </TripPoint>
               </TripPoints>
             </ThermalZone>
           </ThermalZones>
           <CoolingDevices>
             <CoolingDevice>
               <Type>_fan_</Type>
               <Path>/proc/acpi/ibm/fan</Path>
               <WritePrefix>level </WritePrefix>
               <MinState>0</MinState>
               <MaxState>5</MaxState>
               <DebouncePeriod>10</DebouncePeriod>
             </CoolingDevice>
           </CoolingDevices>
         </Platform>
       </ThermalConfiguration>



                                  18 Dec 2018              thermal-conf.xml(5)