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32 .Nd ACPI thermal management subsystem
38 driver provides the thermal management features of the ACPI module.
43 notification interface.
44 The sysctls export properties of each ACPI thermal zone object.
46 There can be multiple thermal zones in a system.
47 For example, each CPU and the enclosure could all be separate thermal
48 zones, each with its own setpoints and cooling devices.
49 Thermal zones are numbered sequentially in the order they appear in
54 driver also activates the active cooling system according to
55 each thermal zone's setpoints.
57 .Bl -tag -width indent
58 .It Va hw.acpi.thermal.min_runtime
59 Number of seconds to continue active cooling once started.
60 A new active cooling level will not be selected until this interval expires.
61 .It Va hw.acpi.thermal.polling_rate
62 Number of seconds between polling the current temperature.
63 .It Va hw.acpi.thermal.user_override
64 If set to 1, allow user override of various setpoints (below).
65 The original values for these settings are obtained from the BIOS and
66 system overheating and possible damage could occur if changed.
67 Default is 0 (no override).
68 .It Va hw.acpi.thermal.tz%d.active
69 Current active cooling system state.
70 If this is non-negative, the appropriate _AC%d object is running.
71 Set this value to the desired active cooling level to force
72 the corresponding fan object to the appropriate level.
73 .It Va hw.acpi.thermal.tz%d.passive_cooling
74 If set to 1, passive cooling is enabled.
75 It does cooling without fans using
77 as the mechanism for controlling CPU speed.
78 Default is enabled for tz0 where it is available.
79 .It Va hw.acpi.thermal.tz%d.thermal_flags
80 Current thermal zone status.
81 These are bit-masked values.
82 .It Va hw.acpi.thermal.tz%d.temperature
83 Current temperature for this zone.
84 .It Va hw.acpi.thermal.tz%d._PSV
85 Temperature to start passive cooling by throttling down CPU, etc.
86 This value can be overridden by the user.
87 .It Va hw.acpi.thermal.tz%d._CR3
88 Temperature to start critical suspend to RAM (S3).
89 This value can be overridden by the user.
90 .It Va hw.acpi.thermal.tz%d._HOT
91 Temperature to start critical suspend to disk (S4).
92 This value can be overridden by the user.
93 .It Va hw.acpi.thermal.tz%d._CRT
94 Temperature to start critical shutdown (S5).
95 This value can be overridden by the user.
96 .It Va hw.acpi.thermal.tz%d._ACx
97 Temperatures at which to switch to the corresponding active cooling
99 The lower the _ACx value, the higher the cooling power.
102 All temperatures are printed in Celsius.
103 Values can be set in Celsius (by providing a trailing
105 or Kelvin (by leaving off any trailing letter).
106 When setting a value by
108 do not specify a trailing decimal (i.e., 90C instead of 90.0C).
110 Notifies are passed to userland via
119 driver sends events with the following attributes:
121 .Bl -tag -width "subsystem" -compact
127 The fully qualified thermal zone object path as in the ASL.
129 An integer designating the event:
131 .Bl -tag -width indent -compact
133 Current temperature has changed.
135 One or more trip points (_ACx, _PSV) have changed.
137 One or more device lists (_ALx, _PSL, _TZD) have changed.
139 Non-standard notify that the system will shutdown if the temperature
140 stays above _CRT or _HOT for one more poll cycle.
151 This manual page was written by
152 .An Takanori Watanabe .