Bug 7445

Summary: Fan always on, reduced battery life - HP Pavillion dv2172ea (dv2000 series)
Product: ACPI Reporter: Marco Romano (romanomarco)
Component: Power-FanAssignee: Konstantin Karasyov (konstantin.karasyov)
Status: REJECTED INVALID    
Severity: normal    
Priority: P2    
Hardware: i386   
OS: Linux   
Kernel Version: 2.6.17 Subsystem:
Regression: --- Bisected commit-id:
Attachments: acpidump output
kernel .config
dmesg output
dmidecode output
cat /proc/interrupts output
lspci -v output

Description Marco Romano 2006-11-01 07:54:32 UTC
Most recent kernel where this bug did not occur: dont'know
Distribution: Ubuntu 6.10
Hardware Environment: HP Pavillion dv2172ea Notebook (dv2000 series) Core 2 Duo
CPU, Bios Ver. F.11
Software Environment: Kernel 2.6.17, Gnome 2.16.1
Problem Description: Using Windows XP gets about 3 hour battery life, the fan
runs often (at lowest speed) but stops when the pc is idle for sometime.
Using Linux gets about 2 hour battery life, the fan is always on (at lowest
speed) and never stops.
Running non processors intensive tasks (Firefox, Thunderbird, Gaim) easily get
the fan to a higher speed level.

If cold booting (when the PC has been off for hours) the fan does stop for
sometime, but only for a few minutes, when the PC gets to its normal running
temperature it goes on and never stops.

Steps to reproduce: Just boot Linux and wait, the fan goes on and never spins down.

Temperatures from the 2 thermal zones are always around 50C or few degrees below
(even when idle)
if stress testing I can get a few degrees past 80C

I get this reading from cat /proc/acpi/thermal_zone/TZS*/*

<setting not supported>
cooling mode:   critical
<polling disabled>
state:                   ok
temperature:             49 C
critical (S5):           98 C
<setting not supported>
cooling mode:   critical
<polling disabled>
state:                   ok
temperature:             51 C
critical (S5):           120 C

I don't know if it's the fan control which is problematic or if the fan control
is ok but the temperatures are too high, triggering the fan always on.
I constantly monitor CPU usage with top -d1 and/or gkrellm and there isn't any
background task hogging the cpu.
Comment 1 Marco Romano 2006-11-01 07:57:00 UTC
Created attachment 9394 [details]
acpidump output
Comment 2 Marco Romano 2006-11-01 08:00:07 UTC
Created attachment 9395 [details]
kernel .config
Comment 3 Marco Romano 2006-11-01 08:00:44 UTC
Created attachment 9396 [details]
dmesg output
Comment 4 Marco Romano 2006-11-01 08:02:09 UTC
Created attachment 9397 [details]
dmidecode output
Comment 5 Marco Romano 2006-11-01 08:02:46 UTC
Created attachment 9398 [details]
cat /proc/interrupts output
Comment 6 Marco Romano 2006-11-01 08:03:16 UTC
Created attachment 9399 [details]
lspci -v output
Comment 7 Konstantin Karasyov 2006-11-02 00:22:59 UTC
No fan control is possible via ACPI functionality on this box.
Comment 8 Marco Romano 2006-11-02 01:30:17 UTC
So fan control is not the problem.

But why fan in linux is always running and in windows not?

What causes the CPU to heat up even if idle?

I thought of a defective laptop, so I returned it to the seller who gave me a
new one: same behaviour.

I can't believe HP can produce such a laptop, considering that the previous
dv1000 series was wonderful and has full linux acpi support.