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    ACPI: thermal trip points are read-only · 11ccc0f2
    Len Brown 提交于
    /proc/acpi/thermal_zone/*/trip_points displays
    what the kernel reads from the BIOS via ACPI.
    
    If you echo a string of ':' deliminted numbers to this file
    then it will change what it displays.
    
    But it shouldn't, since the kernel has no way to communicate
    these changes to ACPI thermal zones.  ACPI thermal zone
    trip points are read-only.
    
    The kernel does have the opportunity to ask the BIOS to change
    the trip points with _SCP - Set Cooling Policy.
    
    Request Active Cooling Mode:
    # echo 0 > /proc/acpi/thermal_zone/*/cooling_policy
    
    Request Passive Cooling Mode:
    # echo 1 > /proc/acpi/thermal_zone/*/cooling_policy
    
    However, in practice it is quite rare for the BIOS
    to support the optional _SCP, and it is even more rare
    for the BIOS to export an _SCP that actually changes
    the trip points.
    Signed-off-by: NLen Brown <len.brown@intel.com>
    11ccc0f2
thermal.c 34.0 KB