[Xorg-driver-geode] Geode LX / ThinCan / General Software BIOS - DDC failing / no EDID info

[Martin-Éric Racine]

On 1/17/08, Jordan Crouse <jordan.crouse at amd.com> wrote:
> On 17/01/08 14:48 -0500, Bart Trojanowski wrote:
> > I got back to looking at why we get no EDID info from some units with
> > General Software BIOS.  I am trying to debug why this is happening.
> >
> > I would love for someone that knows DDC/EDID to suggest things to try at
> > this point.
> >
> > It was mentioned to me in passing that there is a chance that the serial
> > port could be wired on the same pins that are responsible for the
> > DDC/EDID data.  If that is the case, is there an /easy/ way to find out
> > if that has been done on this unit?
>
> Try this:
> http://dev.laptop.org/~jcrouse/gpio-tool.c
>
> If you run it as root, it should show the state of all of the GPIO pins.
> You're looking for IN_AUX1 to _not_ be set on GPIO3, and OUT_AUX1 and
> OUT_AUX2 to _not_ be set on GPIO4.  Section 3.2.8 in the 5536 spec has a
> table that explains this.

Quite nifty tool! The table this tool prints shows two parts:  LOW and
HIGH.  Which one is relevant to us?

-- 
Martin-Éric Racine
http://q-funk.iki.fi