[ltp] T61p, ACPI, temperature sensors after suspend

[Francois Fleuret]

Dear all,

I am the happy owner of a T61p that I use under Linux (Debian), and
there are some weirdness with the temperature measurement after
suspend: The temperatures I get through
/proc/acpi/thermal_zone/THM?/temperature are not the same as any of
the ones appearing in /proc/acpi/ibm/thermal.

For instance, I have:

root@kitten:~ cat /proc/acpi/thermal_zone/THM0/temperature
temperature:             49 C
root@kitten:~ cat /proc/acpi/thermal_zone/THM1/temperature
temperature:             67 C

root@kitten:~ cat /proc/acpi/ibm/thermal
temperatures:   50 44 35 52 50 -128 24 -128 36 48 46 -128 -128 -128
-128 -128

As far as I could check, this does not happen after a fresh reboot and
in that case, the first number of /proc/acpi/ibm/thermal is equal to
/proc/acpi/thermal_zone/THM1/temperature and the fourth is equal to
/proc/acpi/thermal_zone/THM0/temperature.

Beside that unpleasant inconsistency, there is also a fan issue. Even
when the PC is idle, the fan runs at more than 3000rpm:

root@kitten:~ cat /proc/acpi/ibm/fan
status:         enabled
speed:          3089
level:          auto

If I force the fan to level 2, it drops to ~2000 rpm which is far less
noisy (barely noticeable) and the temperature as given by
/proc/acpi/ibm/thermal remains reasonable.

Any idea ?

Regards,

-- 
Francois Fleuret                                http://www.idiap.ch/~fleuret