[REGRESSION] [2.6.37-rc1] Fan noise after suspend to ram/disk

Maciej Rutecki
2010-11-04T16:07:09Z

1.
Last known good kernel: 2.6.36
Bad kernel: 2.6.37-rc1
===============================

2. Problem:
When I resume computer from s2ram/s2disk and current CPU temp is below lowest
trip point, and -- from unknown reason -- fan start in maximum speed it
doesn't turn off (it should).

It doesn't happen always but only when fan starts work and any of trip points
aren't exceed. It seems that system only check temperature when exceed trip
point.
===============================

3. /sys/cass/thermal/ info:

I have:
maciek@gumis:/sys/class/thermal$ ls
cooling_device0 cooling_device2 cooling_device4 cooling_device6
thermal_zone1 thermal_zone3
cooling_device1 cooling_device3 cooling_device5 thermal_zone0
thermal_zone2 thermal_zone4

maciek@gumis:/sys/class/thermal$ cat cooling_device*/type
LCD
Processor
Processor
Fan
Fan
Fan
Fan

===============================

Colling device from 3 to 6 are inform what is current fan speed, for example:
cooling_device3 = 0
cooling_device4 = 0
cooling_device5 = 0
cooling_device6 = 0
Means that fan is off.

cooling_device3 = 0
cooling_device4 = 0
cooling_device5 = 0
cooling_device6 = 1
Means fan works on 40% of full speed (1st trip point is exceed).

cooling_device3 = 1
cooling_device4 = 1
cooling_device5 = 1
cooling_device6 = 1
Means fan works on full speed (all (4) trip points is exceed).
===============================

5. State when fan works on full speed after resume:
maciek@gumis:/sys/class/thermal$ cat cooling_device*/cur_state
0
0
0
1
1
1
1
(Runs on full speed)

maciek@gumis:/sys/class/thermal$ cat thermal_zone0/trip_point_*
256000
critical
78000
active
70000
active
60000
active
50000
active

(It's OK for current CPU temp)

"sensors" command shows:
maciek@gumis:/sys/class/thermal$ sensors
acpitz-virtual-0
Adapter: Virtual device
temp1: +37.0°C (crit = +256.0°C)
temp2: +42.0°C (crit = +90.0°C)
temp3: +33.0°C (crit = +105.0°C)
temp4: +20.0°C (crit = +90.0°C)
temp5: +100.0°C (crit = +110.0°C)

"temp1" in this model of HP notebook is only for debug purposes (I think).
"temp2" shows CPU temp (fan speed depends on it)
"temp5" shows fan speed in % of maximum speed.
===============================

6. I run this command, to "hot" the processor:
"while true; do echo -n; done"
and cancel it, when I see, that first trip point was exceed, and fan starts
working on lower speed.
===============================

7. When it done I saw:
maciek@gumis:/sys/class/thermal$ cat cooling_device*/cur_state
0
0
0
0
0
0
1

Fan works on 40% of full speed. It's OK.

maciek@gumis:/sys/class/thermal$ cat thermal_zone0/trip_point_*
256000
critical
78000
active
70000
active
60000
active
45000
active

Last trip point was changed from 50000 to 45000 because trip point was exceed
(it's OK, fan stops working below 45*C or starts working on 60% speed, above
60*C).

"sensors" show:
maciek@gumis:/sys/class/thermal$ sensors
acpitz-virtual-0
Adapter: Virtual device
temp1: +50.0°C (crit = +256.0°C)
temp2: +48.0°C (crit = +90.0°C)
temp3: +34.0°C (crit = +105.0°C)
temp4: +20.0°C (crit = +90.0°C)
temp5: +40.0°C (crit = +110.0°C)
===============================

Dmesg:
http://unixy.pl/maciek/download/kernel/2.6.37-rc1/gumis/dmesg-2.6.37-rc1.txt

acpidump:
http://unixy.pl/maciek/download/kernel/2.6.37-rc1/gumis/acpidump.dat

Config:
http://unixy.pl/maciek/download/kernel/2.6.37-rc1/gumis/config-2.6.37-rc1

Regards