acpi_tz0: _CRT value is absurd,
ignored (256.0C) (was pr kern/105537)
Chris Whitehouse
cwhiteh at onetel.com
Wed Mar 25 01:42:07 PDT 2009
[Please would you cc me in any reply as I'm not subscribed, thanks.]
Ian Smith wrote:
> On Tue, 24 Mar 2009, Pasi Parviainen wrote:
> > Chris Whitehouse wrote:
> > > Hi, I sent this a while ago but don't think there was a reply. I'm about to
> > > embark on a custom ASL to load in loader.conf as per
> > > http://www.freebsd.org/doc/en/books/handbook/acpi-debug.html but just
> > > wondering if their might be a 'proper' fix on the way. I do have the latest
> > > bios installed.
> >
> > Loading custom ASL with modified _CRT value for temperature zone in
> > question will solve the problem, see below for more information.
> >
> > > Would it help if I installed 8-CURRENT?
> >
> > Probably not, see below.
> >
> > > -------- Original Message --------
> > > Subject: pr kern/105537
> > > Date: Mon, 12 Jan 2009 15:00:49 +0000
> > > From: Chris Whitehouse <cwhiteh at onetel.com>
> > > To: freebsd-acpi at FreeBSD.org
> > >
> > > hi,
> > >
> > > Please would you cc me in any reply as I'm not subscribed, thanks.
> > >
> > > I have the same problem noted in
> > >
> > > http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/105537
> > >
> > > of frequent messages saying
> > >
> > > acpi_tz0: _CRT value is absurd, ignored (256.0C)
> > >
> > > on my HP nc6320 laptop, model RH383ET.
> > >
> >
> > I have HP 6510b and HP 2510p laptops and had same problem with those.
> > Actual problem is that the ACPI thermal code in kernel does sanity-check
> > for temperature values, and accepts only values between 0 - 200 Celsius.
> > To solve the problem you either create custom DSDT which returns 200.0C
> > value instead of 256.0C for thermal zone in question or increase the limit of
> > the sanity-check code of ACPI thermal code (src/sys/dev/acpica/acpi_thermal.c
> > function: acpi_tz_sanity).
> >
> > Proper way to solve this in my opinion is to increase the range of
> > sanity-check function from 0 - 200 Celsius to 0 - 256 Celsius, or at
> > least provide sysctl variable to disable thermal sanity-checks.
>
> Even 200C is absurd, really. That's above the melting point of many
> types of solder (http://www.rfcafe.com/references/electrical/solder.htm)
> while 256C exceeds the melting point of _most_ types of solder. I seem
> to recall that this limit used to be 150C, still hotter than anything
> you actually want to have anywhere on a computer board.
>
> No sense checking sanity to then accept insane values; fix the broken
> ASL. 256 sounds suspiciously like a byte-swapped value, perhaps?
>
> cheers, Ian
>
Getting the ASL in the actual BIOS firmware fixed would be great, but I
tried once to get Asus to correct a byte swapped value without success.
I don't suppose HP will be any more cooperative but I can try. I will
have a look at an acpidump tonight. A custom ASL would at least prove
what is wrong.
Does anyone know what this value is supposed to be measuring?
Chris
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