Re: kernel won't boot on a Cyrix MediaGXm (Geode )

[Ingo Molnar]

* Juergen Beisert <jbe@xxxxxxxxxxxxxx> wrote:

> On Mittwoch, 20. August 2008, Ingo Molnar wrote:
> > * Juergen Beisert <jbe@xxxxxxxxxxxxxx> wrote:
> > > On Mittwoch, 20. August 2008, Ingo Molnar wrote:
> > > > * Samuel Sieb <samuel@xxxxxxxx> wrote:
> > > > > Ingo Molnar wrote:
> > > > >> any patch we should pick up to make your box boot?
> > > > >
> > > > > I've looked through various datasheets and found that the GXm and
> > > > > GXLV Geode processors don't have an incrementor.  I attached two
> > > > > patches. One only calls the incrementor setup for GX1 or better.  The
> > > > > other one removes the incrementor setup entirely.  As the incrementor
> > > > > value differs according to clock speed and we would hope that the
> > > > > BIOS configures it correctly, it is probably the better one to
> > > > > choose.  But I will leave that choice up to you.  Either one works
> > > > > for me. :-)
> > > >
> > > > i went for the commit below and queued it up in tip/x86/urgent - thanks
> > > > Samuel.
> > > >
> > > > what happens if the incrementor is not set up correctly by the BIOS
> > >
> > > The system can freeze. The clock the incrementor modifies is used for
> > > the external SDRAM (something like a delay line or jitter reduction).
> > > Thats why its setting depends on the core clock speed.
> >
> > so, what's the recommendation - is the patch fine? (which removes
> > incrementor setting, leaving it to the BIOS)
> 
> In my environment I need the incrementor setting in accordance to the 
> CPU core frequency, as my BIOS sets a wrong value. Removing it is no 
> solution for me.
> 
> But: There where a few bug reports in the last weeks, and all had 
> problems when the incrementor setting is changed inside the kernel. 
> Seems only my BIOS is broken.
> 
> So I vote for removing the incrementor setting. I can life with a 
> local patch for my kernels.

is there any way to specifically identify your board/bios combo, like a 
DMI string? I have absolutely no problem with adding a quirk for your 
box. In fact i'd much prefer that solution than you having to carry a 
local patch - quirks are local only in the rarest of circumstances.

Mind doing a quirk patch ontop of the patch below, for us to apply for 
v2.6.27?

	Ingo

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