[ltp] Re: tpfand configuration for an X200s

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Tue, 2 Dec 2008 21:12:59 -0200


On Tue, 02 Dec 2008, Christoph Bier wrote:
> Henrique de Moraes Holschuh schrieb am 02.12.2008 15:13:
> > On Tue, 02 Dec 2008, Christoph Bier wrote:
> >> Henrique de Moraes Holschuh schrieb:
> >>> On Tue, 02 Dec 2008, Christoph Bier wrote:
> >>> The sensors you get from thinkpad-acpi are discrete thermal sensors, located
> >>> in the various parts of the mainboard, inside battery packs, etc.
> >>
> >> Just to get it right: Does tpfand use/show thinkpad-acpi's data?
> > 
> > Yes, and it is not the most brilliant implementation on how to interface to
> > thinkpad-acpi, either.
> 
> So you wouldn't recommend its usage? But then, how can I influence

I don't recommend using any fan control loop application, period.
This is not particular to tpfand.

My comment was caused because I noticed that tpfand is still using
deprecated interfaces (/proc/acpi/ibm/*) and it does pretty basic
error handling (but it is not bad).

> the fan's behaviour? Should I load ibm_acpi that is not loaded by

ibm-acpi is gone.  That driver has been renamed to thinkpad-acpi for a
long time now.

You need to load thinkpad-acpi with the "fan_control=1" parameter to
enable fan control.  Otherwise, it will only let you read the fan
tachometer...

> default? You see, I'm not very familiar with this. To be honest, the
> information provided by the ThinkWiki is surely helpful but also
> confusing because there are so many ways to solve a problem. I know
> http://www.thinkwiki.org/wiki/ACPI_fan_control_script but I don't
> know which solution to choose.

Let me tell you one thing that you MUST keep in mind:

Unless you *really* know better, using any sort of fan control to slow
down the fan is never completely safe.  The thinkpad wanted the fan
faster for a reason, and unless you actually are SURE that it was for
a bad reason, there is risk in overriding it.

So take it from me, the guy who writes the code that goes in the
kernel to let you do fan control: do not do fan control for frivolous
reasons.

If your fan is noisy, get it fixed.  If it needs to run because the
thinkpad is getting too hot, forcing it to slow down is the WRONG
answer.

> I take your answer as an indication that fan control should work
> out-of-the-box without user interference. What can I do---as a

Correct.  On thinkpads, it is supposed to work out-of-the-box even if
the operating system has crashed.

> common user, I'm not a programmer---to improve the situation?

As I said, it is not supposed to be too noisy.  Check with other X200
users, tell us the RPM in your fan when it is being noisy.  And after
you have some idea whether it is normal or not, call Lenovo and
complain that the thing is broken [if it is too noisy].

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh