fan control on evo n800v

fan control on evo n800v

Post by Yaye » Tue, 18 Jan 2005 22:51:57


I have a compaq evo n800v on which I want to use linux.

I have install Mandrake 10.1 and all seem working except the fan
control... Acpi seem ok and seeing the dmesg, the dsdt of my laptop is
used (see dmesg at the end of the post).

In fact, when I boot, the processor's fan is active (but not detected by
acpi) :

When I do an acpi -V, I've a message like this :
Battery 1 : charged, 100%
Thermal 1 : ok, 46.0 degrees C
Thermal 2 : ok, 43.0 degrees C
Thermal 3 : ok, 16.0 degrees C

Something else is supprising :

When I use more cpu, the temperature increase and when I reach 55
degrees C, the fan should start. Of course, because it was running,
nothing is changed... except it's detected !

acpi -V gives :

Battery 1 : charged, 100%
Thermal 1 : active[3], 58.0 degrees C
Thermal 2 : ok, 45.0 degrees C
Thermal 3 : ok, 16.0 degrees C

And when the temperature goes down 41 degrees C, the fan stop !!

So I'm looking for a way to stop fan at boot time : it's active even if
the temperature is 30 degrees... if I do simple think which dont use to
many processor time (just emacs for example), the temperature never
increase and the fan is always on...

Thank you in advance for your help and sorry for my english (I'm french)



dmesg :

Linux version ( XXXX@XXXXX.COM ) (gcc version
3.4.1 (Mandrakelinux (Alpha 3.4.1-3mdk)) #1 Fri Oct 1 12:53:41 CEST 2004
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000001ffd0000 (usable)
BIOS-e820: 000000001ffd0000 - 000000001fff0c00 (reserved)
BIOS-e820: 000000001fff0c00 - 000000001fffc000 (ACPI NVS)
BIOS-e820: 000000001fffc000 - 0000000020000000 (reserved)
0MB HIGHMEM available.
511MB LOWMEM available.
On node 0 totalpages: 131024
DMA zone: 4096 pages, LIFO batch:1
Normal zone: 126928 pages, LIFO batch:16
HighMem zone: 0 pages, LIFO batch:1
DMI 2.3 present.
ACPI: RSDP (v000 COMPAQ ) @ 0x000f60c0
ACPI: RSDT (v001 COMPAQ CPQ004A 0x26040420 CPQ 0x00000001) @ 0x1fff0c84
ACPI: FADT (v002 COMPAQ CPQ004A 0x00000002 CPQ 0x00000001) @ 0x1fff0c00
ACPI: SSDT (v001 COMPAQ CPQGysr 0x00001001 MSFT 0x0100000e) @ 0x1fff69b8
ACPI: SSDT (v001 COMPAQ CPQMag 0x00001001 MSFT 0x0100000e) @ 0x1fff6ac6
ACPI: DSDT (v001 COMPAQ EVON800 0x00010000 MSFT 0x0100000e) @ 0x00000000
ACPI: PM-Timer IO Port: 0x1008
Built 1 zonelists
No local APIC present or hardware disabled
Initializing CPU#0
Kernel command line: BOOT_IMAGE=linux ro root=305 acpi=on
resume=/dev/hda7 splash=silent
bootsplash: silent mode.
PID hash table entries: 2048 (order 11: 16384 bytes)
Detected 2392.636 MHz processor.
Using pmtmr for high-res timesource
Console: colour dummy device 80x25
Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
Memory: 515252k/524096k available (1859k kernel code, 8080k reserved,
578k data, 200k init, 0k highmem, 0k BadRAM)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Calibrating delay loop... 4734.97 BogoMIPS
Security Scaffold v1.0.0 initialized
SELinux: Disabled at boot.
Capability LSM initialized

fan control on evo n800v

Post by Torsten Wa » Thu, 20 Jan 2005 02:12:42

i Yayel,
I cannot help a lot just give some ideas. The fan is running everytime
during boot-up even with Windows-OS. This is because the ACPI is not
activate at this time and the bios starts with a "secure" means full
speed fan mode. Otherwise you will run in trouble if you use your Evo up
to the limit, shut it down and then restart it directly (e.g. a system
crash). During boot up the CPU will die because of the released heating.
This is the reason, that during boot up th fan run at full speed to be
sure everything goes fine. However, after starting ACPI it should detect
the CPU temperature and decrease the fan-speed.

I used a Suse-Live CD 9.2. and it works well with it (Evo 800w). Suse
announced better ACPI-support. You may give it a try.


Yayel wrote:


fan control on evo n800v

Post by Jg-Volker » Fri, 18 Feb 2005 22:46:36

> ...
on my compaq presario 2825ea (which uses the same bios as the evo n800v)
with Debian sarge I use a script /etc/init.d/fan-switchoff:

# Switch of the cooling fan (to correct kernel ACPI flaw).


test -r $TZ1_TEMPERATURE || exit 0
test -w $FAN_STATE || exit 0

temp=`cat $TZ1_TEMPERATURE | awk '{ print $2 }'`
if [ $temp -lt 45 ]; then
echo "Switching off cooling fan."
echo -n 0 > $FAN_STATE
echo -n 3 > $FAN_STATE

exit 0

which is linked to /etc/rcS.d/S71fan-switchoff. I don't use ACPI
modules, all is compiled into the kernel. Otherwise you have to load the
"fan" and "thermal" module before running this script. Also the
directory names in /proc/acpi/fan/ may be something else.
For SuSE you place these code lines into the script /etc/init.d/boot.local.

The relevant thing are the last two echo commands.
I found a hint for this on