Bug#487287: acpi: Negative value is show for temperature, fan constantly on

[maximilian attems <max@stro.at>]

On Sun, Jun 29, 2008 at 05:17:07PM +0200, Adolf Winterer wrote:
> Am Sonntag, 22. Juni 2008 12:48 schrieb Michael Meskes:
> > On Sun, Jun 22, 2008 at 10:43:25AM +0200, Adolf Winterer wrote:
> > > The directory /sys/class/thermal does not exist.
> >
> > Which kernel do you run? Looks like a strange configuration here.
> >
> > > Look at the temperature!
> > >
> > > $ cat /proc/acpi/thermal_zone/THRM/temperature
> > > temperature:             -73 C
> >
> > Yes, it reports a negative temperature. But this is reported by the
> > kernel. acpi only reads this information and displays it. The problem
> > doesn't seem to be in acpi, but in the kernel itself.
> 
> I did some more research regarding ACPI and found out that on both systems 
> there is a flawed ACPI DSDT.
> 
> Using acpidump I stored the DSDT into a file and disassembled it with iasl. 
> When comiling the file back into a binary file I get one warning and two 
> errors on both systems which look quite similar.
> 
> # iasl -sa dsdt.dsl
> 
> Intel ACPI Component Architecture
> ASL Optimizing Compiler version 20061109 [May 15 2007]
> Copyright (C) 2000 - 2006 Intel Corporation
> Supports ACPI Specification Revision 3.0a
> 
> dsdt.dsl   378:     Method (\_WAK, 1, NotSerialized)
> Warning  1079 -                 ^ Reserved method must return a value (_WAK)
> 
> dsdt.dsl   419:             Store (Local0, Local0)
> Error    4049 -                         ^ Method local variable is not 
> initialized (Local0)
> 
> dsdt.dsl   424:             Store (Local0, Local0)
> Error    4049 -                         ^ Method local variable is not 
> initialized (Local0)
> 
> ASL Input:  dsdt.dsl - 5129 lines, 163766 bytes, 1797 keywords
> Compilation complete. 2 Errors, 1 Warnings, 0 Remarks, 571 Optimizations
> 
> I found a suggestion how to fix the warning, but did not find anything for the 
> errors. The code looks like that:
> 
>     Scope (\_SI)
>     {
>         Method (_MSG, 1, NotSerialized)
>         {
>             Store (Local0, Local0)
>         }
> 
>         Method (_SST, 1, NotSerialized)
>         {
>             Store (Local0, Local0)
>         }
>     }
> 
> I do not understand a single word from it, so there is not a real chance to 
> fix it myself.
> 
> Some time ago I read about a DSDT fix that has been removed from the kernel, 
> but I do not know if this is related to the problem we see here.

please report bug upstream in bugzilla.kernel.org one shouldn't need to
fiddle with DSDT tables.

and please let us know the upstream bug number.

thanks

-- 
maks