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Date: Tue, 15 Jul 2008 09:31:29 -0600
From: "David Hubbard" <david.c.hubbard@gmail.com>
To: "Jean Delvare" <khali@linux-fr.org>
Subject: Re: [RFC] (almost) booting allyesconfig -- please don't poke super-io
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Hi Jean,

On Tue, Jul 15, 2008 at 2:36 AM, Jean Delvare <khali@linux-fr.org> wrote:
>> Is there any way to use lspci and start at the LPC bridge, then find
>> the SuperIO chip's IO address? What about ACPI tables? Perhaps probing
>> logic could look for an LPC bridge before probing certain IO addresses
>> even if the addresses are not in the LPC bridge config.
>
> I always assumed that there was no way to know in advance if a
> Super-I/O (LPC) chip was present or not, let alone the exact model of
> the chip. The I/O addresses are decoded by the Super-I/O chip itself,
> and in general it has no relation to PCI. And I've never seen ports
> 0x2e/0x2f nor 0x4e/0x4f listed in /proc/ioports.
>
> But of course if there is a way to know, we should use it. Avoiding
> random access to I/O ports, even if they are relatively standard in
> this case, is always good.

I looked at my lspci output and did a little researching, and I think
the only thing we can deduce is that there is an LPC bridge, so
looking for a SuperIO is a good idea. If there is no LPC bridge
listed, I can't say whether probing the ports is a good idea or not.

David