Re: R: [Bug #14886] Asus P2B-DS not detected as SMP moterboard

From: Dmitry Artamonow
Date: Tue Jan 26 2010 - 11:22:10 EST

On 20:40 Mon 11 Jan , Rafael J. Wysocki wrote:
> On Monday 11 January 2010, flinco@xxxxxxxxx wrote:
> > Tried The issue is still present.
> Thanks for the update.
> Rafael

(I have some troubles with registering on kernel bugzilla, so posting here,
adding people from bug to CC: list)

I'm also using P2B-DS and can confirm that starting with kernel 2.6.32
SMP stopped working (and don't work still - tested with current git
v2.6.33-rc5-238-g158c168) The issue seems to have something to do with the
fact that ACPI is blacklisted on P2B-DS. I used to workaround this bug
on newer kernels (>=2.6.32) by passing "acpi=force" in kernel arguments.
Finally, yesterday I found some time to write simple automated bisection
script and leaved it to run on machine overnight. Here's result:
e5b8fc6ac158f65598f58dba2c0d52ba3b412f52 is the first bad commit
commit e5b8fc6ac158f65598f58dba2c0d52ba3b412f52
Author: Len Brown <len.brown@xxxxxxxxx>
Date: Tue Jul 7 23:22:58 2009 -0400

ACPI: check acpi_disabled in acpi_table_parse() and acpi_table_parse_entries()

Allow consumers of the acpi_table_parse()/acpi_table_parse_entries() API
to gracefully handle the acpi_disabled=1 case via return value
rather than checking the global flag themselves.

Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>

I re-checked this result and yes - reverting this commit on both 2.6.32 and
current git (v2.6.33-rc5-238-g158c168) makes problem go away.

Best regards,
Dmitry "MAD" Artamonow

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