[ltp] Re: Tracking down a EC firmware bug (fan reading)

Marco Gaiarin linux-thinkpad@linux-thinkpad.org
Wed, 4 Oct 2006 12:24:52 +0200

Mandi! Henrique de Moraes Holschuh
  In chel d? si favelave...

HdMH>   T-series: T23 and later (T43 26xx know affected)

T23, i have it. ;)

HdMH>         Make sure you don't have any fan control scripts or anything else
HdMH>         that might be writing to the fan control register!   This is *very*

How i can be sure of this? I'm using a plain ubuntu 6.06, and i've not load
the laptop-mode package.

A simple:

	grep fan /etc/init.d/*

report nothing. Suffices?

HdMH>         If you *know* for sure that your ThinkPad powers up in automatic
HdMH>         fan control (i.e. it varies by itself the fan speed when it gets
HdMH>         hotter, etc) -- AFAIK all ThinkPads do this, but... -- then you
HdMH>         don't need to sleep to RAM.

I'm pretty sure, but i've hear my T23 do some more noise in very rare case,
as for kernel compilation (but 'm using the ubuntu kernel).

HdMH>         If your ibm-acpi is patched for fan control, check whether "cat
HdMH>         /proc/acpi/ibm/fan" reports that the fan is enabled *and* in auto
HdMH>         mode.  If it reports anything different, then you have the bug.

gaio@aurora:~$ cat /proc/acpi/ibm/fan
status:         enabled
speed:          0
commands:       enable, disable

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