Bug 1359

Summary:	Fan is being turned on and off in 6 secs intervals
Product:	ACPI	Reporter:	Martin Mokrejs (mmokrejs)
Component:	Power-Fan	Assignee:	Len Brown (lenb)
Status:	REJECTED INVALID
Severity:	normal	CC:	acpi-bugzilla
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.4.23-pre7	Subsystem:
Regression:	---	Bisected commit-id:

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:
acpi-20030918

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. 
 
thanks, 
-Len