Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources

[Jesse Barnes <jesse.barnes@intel.com>]

On Wednesday, May 2, 2007 4:54 pm Jesse Barnes wrote:
> > What happens if you take out the chipset register detection, does
> > the MCFG table give you the same result? Wonder if they're doing
> > something funny with start/end bus values or something in their
> > table. There's some code in my patch that prints out the important
> > data from the MCFG table, can you tell me what that shows with the
> > chipset detection taken out?
>
> Yeah, I'll look a little more closely.  It could also be that another
> register needs tweaking somewhere to actually get the bridge to
> decode the space.
>
> > If that doesn't provide any useful information, I think we may need
> > some assistance from Intel chipset/motherboard people to figure out
> > what is going on here..
>
> I'm talking with them now, hopefully they'll shed some light on it.

I did a little more debugging this morning, and found that I can 
actually do reads from the space described by ACPI and the device 
register, but later when ACPI actually scans the root bridges, it 
hangs.  Specifically the call to pci_acpi_scan_root in 
pci_root.c:acpi_pci_root_add() never seems to return.

I'll walk through that logic when I get back to my test box, but it's 
also worth noting that Vista's MCFG on this machine apparently works ok 
too.

Jesse