Re: [ACPI] Re: [BKPATCH] LAPIC fix for 2.6

From: Sérgio Monteiro Basto
Date: Sun Oct 10 2004 - 16:21:08 EST


On Sun, 2004-10-10 at 20:04, Maciej W. Rozycki wrote:
> On Sun, 10 Oct 2004, Linus Torvalds wrote:
>
> > > Hi Linus, please do a
> > >
> > > bk pull bk://linux-acpi.bkbits.net/26-latest-release
> >
> > Ok, this version of the patch suddenly looks like a real bug-fix in that
> > it now makes the command line options "lapic"/"nolapic" a lot more
> > logical.
>
> Hmm, any particular reason to keep the local APIC disabled by default?
> Most BIOS vendors keep it disabled just because it's easier to get stuff
> set up this way -- with the APIC enabled you need to do the same steps to
> program the 8259As as with the APIC disabled, plus program the APIC
> itself, which provides no gain to BIOS itself or to DOS, so why bother?
>
> Maciej
>

The problem is: trying enable some local apic's (for example on via
mother boards on my laptop), cause many problem, like hang on boot (with
ACPI), hang on Fn-F3 (video switch), power-off fails, etc. and no one
knows how resolved the problem.
So keep it disable if BIOS vendors say so, can be reasonable idea.

--
Sérgio M. B.

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