Subject: Re: ISA direct config of ACPI devices
To: Quentin Garnier <cube@cubidou.net>
From: Matthias Drochner <M.Drochner@fz-juelich.de>
List: tech-kern
Date: 11/23/2007 18:18:19
cube@cubidou.net said:
> It maps the ACPI tree on our device tree with the result of attaching
> those devices to the "acpipcib" device (because that's where they
> appear in the ACPI tree)
Interesting -- this looks like the way Windows does it. Only
that they call it LPC-bus which matches the hardware better.
(I didn't check yet what the diffences between ISA and LPC are.
I'd guess LPC is logically reduced and physically accelerated.)
But how do you know if you find eg a UAR1=PNP0501 entry in
the ACPI _SB namespace that it should be put below your acpipcib
node in the tree? I haven't found any ISA bus object in the
ACPI spec, nor anything in the device nodes which could tell
"this is an ISA device". And you can't tell from address ranges
because we have subtractive decoding on those bridges.
So there is some heuristics or guessing, or am I missing something?
best regards
Matthias
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