Bug 1359 - Fan is being turned on and off in 6 secs intervals
Fan is being turned on and off in 6 secs intervals
Product: ACPI
Classification: Unclassified
Component: Power-Fan
i386 Linux
: P2 normal
Assigned To: Len Brown
Depends on:
  Show dependency treegraph
Reported: 2003-10-15 02:15 UTC by Martin Mokrejs
Modified: 2004-05-30 14:48 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.4.23-pre7
Tree: Mainline
Regression: ---


Description Martin Mokrejs 2003-10-15 02:15:37 UTC
Distribution: Gentoo
Hardware Environment: ASUS L3800C, 1GB RAM, Pentium 4M
Software Environment:
Problem Description:

When /proc/acpi/thermal_zone/THRM/cooling_mode 
is set to passive, temperature is between 74-76 oC, fan is being turned on and
off evry about 6 seconds. To solve the problem temporarily is to set cooling
mode to active. Then the fan cools system for a some longer time that 6 seconds,
but something in acpi triggers the cooling mode to passive and then again fan is
turned on and off like crazy:

vrapenec root # cat /proc/acpi/thermal_zone/THRM/trip_points 
critical (S5):           95 C
passive:                 75 C: tc1=1 tc2=1 tsp=100 devices=0xc1c3defc 
active[0]:               90 C: devices=0xc1c30efc 
vrapenec root # cat /proc/acpi/thermal_zone/THRM/temperature 
temperature:             76 C
vrapenec root # 

Steps to reproduce:
Comment 1 Shaohua 2003-10-15 17:44:08 UTC
Martin, as I have mentioned before, the DSDT can't control the real fan (I 
mean the hardware) at all in your machine. I guess if you strip ACPI, you will 
get the same symptom.
Comment 2 Len Brown 2003-11-13 10:08:13 UTC
Please boot with acpi=off and see if the fan does the same thing 
and the Linux ACPI code has nothing to do with this -- 
or if the Linux ACPI code is implicated. 
If Linux ACPI code is implicated, please attach acpidmp and dmesg output. 

Note You need to log in before you can comment on or make changes to this bug.