7.10 support of new AMD PowerNow! (family 0x11 and beyond)

[Langsdorf, Mark]

> > In late November, I submitted a few patches to this list
> > for consideration in an Ubuntu 7.10 update release.  The
> > purpose was to provide support for PowerNow! in AMD's
> > forthcoming Family 0x11 processors.  There was a short
> > patch submittted on 11/27 that addressed Family 0x11
> > parts, and a much larger patch on 11/29 that handled all
> > future AMD parts.
> >
> > There was never much discussion of them that I saw, and
> > so I don't know which, if either, was adapted.  Linux
> > PowerNow! support of family 0x11 parts is becoming 
> > important to some of our OEMs, so I'm trying to determine
> > what the Ubuntu kernel community did.  Would someone 
> > please enlighten me?
> >   
> Mark - We have reviewed the November patch, but see some problems with
> it. It appears to change the default behavior of the 
> function, which we are loath to do in a security update.

There were 2 November patches: a small one that addresses 0x11
only, and a larger one that addresses all future families.

I'm not sure how either patch changes the default behavior.
Would you explain?

* The small patch adjusts the calculation of frequency from
the Frequency ID based on the family number.  This is necessary
to get PowerNow! working on 0x11 parts, since the 0x10 calculation
returns the incorrect frequency and the driver assumes there is
an ACPI error.

* The large patch removes Frequency ID (fid) from the driver 
altogether, because fid is not part of the architectural
definition and is not guaranteed to be supported on future
parts.

> I also do not see this patch upstream in 2.6.24-rc8. Why not?

The small one was superceded by the large patch.  The majority
of the large patch code (and the more relevant portion) is in
2.6.24-rc8 as far as I can tell.  I'll go nag Dave Jones about
getting the rest of the patch in.  The full patch is in
2.6.24-rc8-mm1.

-Mark Langsdorf
Operating System Research Center
AMD