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Diffstat (limited to 'Documentation/ibm-acpi.txt')
| -rw-r--r-- | Documentation/ibm-acpi.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/ibm-acpi.txt b/Documentation/ibm-acpi.txt index cbd3a603a7e..0132d363feb 100644 --- a/Documentation/ibm-acpi.txt +++ b/Documentation/ibm-acpi.txt @@ -670,6 +670,26 @@ example: modprobe ibm_acpi hotkey=enable,0xffff video=auto_disable +The ibm-acpi kernel driver can be programmed to revert the fan level +to a safe setting if userspace does not issue one of the fan commands: +"enable", "disable", "level" or "watchdog" within a configurable +ammount of time. To do this, use the "watchdog" command. + + echo 'watchdog <interval>' > /proc/acpi/ibm/fan + +Interval is the ammount of time in seconds to wait for one of the +above mentioned fan commands before reseting the fan level to a safe +one. If set to zero, the watchdog is disabled (default). When the +watchdog timer runs out, it does the exact equivalent of the "enable" +fan command. + +Note that the watchdog timer stops after it enables the fan. It will +be rearmed again automatically (using the same interval) when one of +the above mentioned fan commands is received. The fan watchdog is, +therefore, not suitable to protect against fan mode changes made +through means other than the "enable", "disable", and "level" fan +commands. + Example Configuration --------------------- |