Re: Geode-GX1 processor in 2.6.21

From: Alan Cox
Date: Mon Apr 30 2007 - 10:59:13 EST

> > In arch/i386/kernel/cpu/cyrix.c function geode_configure() tries to enable
> > the "suspend on halt power saving feature". This is the line:
> >
> > setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);

That will go wrong

> > #define setCx86(reg, data) do { \
> > outb((reg), 0x22); \
> > outb((data), 0x23); \
> > } while (0)
> >
> > Maybe the compiler does the wrong thing if someone uses these macros in the
> > same instruction?
> Sounds quite likely.

The problem is the macro evaluates to

outb(reg, 0x22);
[Then the getCx86]
outb(data, 0x23);

which isn't valid for 6x86 control. Looks like someone overoptimised it.

Either make it "inline" or split it up and it'll work

> Also, it would probably be good to convert these macros into inline functions
> in this header.

Agreed - they must be issued in order in the right way as they are CPU
level magic.
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