Re: Bug report: the extended PCI config space is missed with 6.2-rc2

[Bjorn Helgaas]

On Fri, Jan 06, 2023 at 12:22:09AM +0000, Luck, Tony wrote:
> > ...and Dave, who reported that CXL enumeration was busted in -rc2, says
> > this patch fixes that. So you can also add:
> >
> > Tested-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> 
> Also seems good for my Broadwell/EDAC system.
> 
> Boot messages mentioning MMCONFIG are:
> 
> $ dmesg | grep MMCONFIG
> PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
> PCI: not using MMCONFIG
> PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
> PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] reserved in ACPI motherboard resources or EFI

This part looks ok.

> PCI: MMCONFIG for 0000 [bus00-7f] at [mem 0x80000000-0x87ffffff] (base 0x80000000) (size reduced!)
> acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended configuration space under this bridge
> acpi PNP0A03:01: fail to add MMCONFIG information, can't access extended configuration space under this bridge
> acpi PNP0A08:02: fail to add MMCONFIG information, can't access extended configuration space under this bridge
> acpi PNP0A08:03: fail to add MMCONFIG information, can't access extended configuration space under this bridge

But the rest of this still looks like a regression.  From your
previous dmesg log:

  PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
  PNP0A03:00: host bridge to domain 0000 [bus ff]
  PNP0A03:01: host bridge to domain 0000 [bus bf]
  PNP0A03:02: host bridge to domain 0000 [bus 7f]
  PNP0A03:03: host bridge to domain 0000 [bus 3f]
  PNP0A08:00: host bridge to domain 0000 [bus 00-3e]
  PNP0A08:01: host bridge to domain 0000 [bus 40-7e]
  PNP0A08:02: host bridge to domain 0000 [bus 80-be]
  PNP0A08:03: host bridge to domain 0000 [bus c0-fe]

That MMCONFIG space should cover all those buses, but something is
going wrong.

I'll look at this more tomorrow.

Bjorn