[Xorg-driver-geode] Geode LX video testing results

[Bart Trojanowski]

* Martin-?ric Racine <q-funk at iki.fi> [071214 01:26]:
> On 12/14/07, Jordan Crouse <jordan.crouse at amd.com> wrote:
> 
> > This is on the Thincan?  If so, then I'm confused - I thought the
> > thincan didn't have a VGA BIOS, and the _only_ way we're getting
> > into that function is if LXCheckVGA returns TRUE.
> 
> ThinCan either has General Software BIOS with the whole shebang or
> LinuxBIOS with the VGA ROM blob, depending on the configuration.

I don't know if this is conclusive but I do have iomem mapped in the
VGA/CGA regions:

    cat /proc/iomem | grep -i A0000
    000a0000-000bffff : Video RAM area

    cat /proc/iomem | grep -i c000
    000c0000-000c7fff : Video ROM

> > But, lets pretend that for as of yet unexplained behavior, somehow
> > the CheckVGA function is returning true.

LXCheckVGA() must be returning TRUE.  I know we are hitting the
GeodeProbeDDC() function:

    useVGA = LXCheckVGA(pScrni);
   
    if (flags & PROBE_DETECT) { 
        if (useVGA)
            GeodeProbeDDC(pScrni, pEnt->index); // dies here on -configure
        return TRUE; 
    } 

> > So then, we assume that VGA is there, and we merrily go off and and
> > try to get the DDC information, which we know will blow up because
> > the Thincan doesn't have the DDC pins enabled, but rather the
> > second serial port.

I'll buy that.

> > This is badness, but there really isn't anything that the driver can
> > do in this situation - at some point, we have to make certain
> > assumptions.  The assumption that DDC will at least not blow up if
> > VGA is present is an assumption that I can feel good about.  

Again, agreed.

Based on my last results, X -configure still freezes, but X -config
xorg.conf runs if I adds sleep(1)'s all over the place (narrowing down
is still in my TODO for today).

> > DDC may also be blowing up on General Software, but probably for
> > other reasons then the pins being muxed.
> >
> > The third option is that we just plain screwed up the DDC function -
> > I'll compare to Intel and verify.

I am more then willing to try any other patches you may come up with :)

-Bart

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