ACPI SCI flags

Takayoshi Kochi kochi at
Sun Apr 25 09:41:14 PDT 2004


From: Nate Lawson <nate at>
Subject: Re: ACPI SCI flags
Date: Wed, 21 Apr 2004 19:48:52 -0700 (PDT)

> On Fri, 9 Apr 2004, Brown, Len wrote:
> > Nate,
> >
> > I think we finally got the vague part of the ACPI spec
> > regarding SCI polarity/trigger cleared up.  In Linux
> > as of 2.4.26 and 2.6.5 we now do this:
> >
> > PIC mode:
> > 	force level/low via ELCR always.
> Did you find that made a difference on some systems?  If so, which ones?
> The opinion here was that ELCR is probably EISA-only.

Kanaoka-san reported that if SCI is not set level-trigger,
the SCI doesn't work properly on his laptop.
It (Libretto L3) has ALi chipsets (1543 south bridge).

When I tested on my laptop (ThinkPad X31, Intel ICH4),
it seemed that the setting of ELCR didn't make any difference, though.

Takayoshi Kochi

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