[PATCH 08/11] kernel/x86: move SCx200 support from generic to geode

[Elliott Mitchell]

On Wed, Nov 15, 2023 at 05:05:00AM +0100, Stefan Lippers-Hollmann wrote:
> 
> On 2023-11-14, Elliott Mitchell wrote:
> > Date: Thu, 13 Apr 2023 17:07:20 -0700
> >
> > The SCx200 is part of the Geode platform.  As such generic x86
> > doesn't need the driver, but Geode does.
> 
> Not objecting against this patch, just taking it as an opportunity to ask
> an orthogonal question...
> 
> Are three 32-bit x86 subtargets still needed/ warranted?
> I mean all of these targets are basically obsolete and very low-end/
> low-speed (hard to compete against mt7621a), so do the subtarget
> specific optimizations really make sense anymore (are there any rough
> performance comparisons or other reasons to keep them separate)?

I stated this in a previous message.  In my view the current "generic"
target is worthless.  It is only useful to a small number of computers
and not worthy of having a specific target.

I would suggest it may be worthwhile splitting "64" besides having
virtual machine targets.  Early amd64 computers did feature AGP and PATA,
but those rapidly disappeared shortly after the architecture came into
existance.

Perhaps "old64" and "current64"?

Dunno.  "geode" seems worthwhile since the processors were manufactured
into 2019 and they are semi-embedded.  Having 2 generalized/desktop x86
targets seems too few, but 3 generalized/desktop x86 targets seems too
many.

Another way to evaluate is to consider the number of years covered by a
given target:

geode: 1999-2019
generic: 2000-2004
legacy: 1996-2007
64: 2003-2023

Which clearly paints "generic" as the one to eliminate.  Whereas "64"
should be under consideration for splitting.


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