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ACPI_THERMAL(4) Kernel Interfaces Manual ACPI_THERMAL(4) NAME acpi_thermal -- ACPI thermal management subsystem SYNOPSIS device acpi DESCRIPTION The acpi_thermal driver provides the thermal management features of the ACPI module. This driver has a sysctl(8) interface and a devd(8) noti- fication interface. The sysctls export properties of each ACPI thermal zone object. There can be multiple thermal zones in a system. For example, each CPU and the enclosure could all be separate thermal zones, each with its own setpoints and cooling devices. Thermal zones are numbered sequen- tially in the order they appear in the AML. The acpi_thermal driver also activates the active cooling system ac- cording to each thermal zone's setpoints. SYSCTL VARIABLES hw.acpi.thermal.min_runtime Number of seconds to continue active cooling once started. A new active cooling level will not be selected until this inter- val expires. hw.acpi.thermal.polling_rate Number of seconds between polling the current temperature. hw.acpi.thermal.user_override If set to 1, allow user override of various setpoints (below). The original values for these settings are obtained from the BIOS and system overheating and possible damage could occur if changed. Default is 0 (no override). hw.acpi.thermal.tz%d.active Current active cooling system state. If this is non-negative, the appropriate _AC%d object is running. Set this value to the desired active cooling level to force the corresponding fan ob- ject to the appropriate level. hw.acpi.thermal.tz%d.passive_cooling If set to 1, passive cooling is enabled. It does cooling with- out fans using cpufreq(4) as the mechanism for controlling CPU speed. Default is enabled for tz0 where it is available. hw.acpi.thermal.tz%d.thermal_flags Current thermal zone status. These are bit-masked values. hw.acpi.thermal.tz%d.temperature Current temperature for this zone. hw.acpi.thermal.tz%d._PSV Temperature to start passive cooling by throttling down CPU, etc. This value can be overridden by the user. hw.acpi.thermal.tz%d._CR3 Temperature to start critical suspend to RAM (S3). This value can be overridden by the user. hw.acpi.thermal.tz%d._HOT Temperature to start critical suspend to disk (S4). This value can be overridden by the user. hw.acpi.thermal.tz%d._CRT Temperature to start critical shutdown (S5). This value can be overridden by the user. hw.acpi.thermal.tz%d._ACx Temperatures at which to switch to the corresponding active cooling level. The lower the _ACx value, the higher the cool- ing power. All temperatures are printed in Celsius. Values can be set in Celsius (by providing a trailing "C") or Kelvin (by leaving off any trailing letter). When setting a value by sysctl(8), do not specify a trailing decimal (i.e., 90C instead of 90.0C). NOTIFIES Notifies are passed to userland via devd(8). See /etc/devd.conf and devd.conf(5) for examples. The acpi_thermal driver sends events with the following attributes: system ACPI subsystem Thermal type The fully qualified thermal zone object path as in the ASL. notify An integer designating the event: 0x80 Current temperature has changed. 0x81 One or more trip points (_ACx, _PSV) have changed. 0x82 One or more device lists (_ALx, _PSL, _TZD) have changed. 0xcc Non-standard notify that the system will shutdown if the temperature stays above _CRT or _HOT for one more poll cycle. SEE ALSO acpi(4), cpufreq(4), acpidump(8) AUTHORS Michael Smith This manual page was written by Takanori Watanabe. FreeBSD 14.3 November 21, 2022 ACPI_THERMAL(4)
NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | NOTIFIES | SEE ALSO | AUTHORS
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