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

From: Luck, Tony
Date: Thu Jan 05 2023 - 19:22:26 EST


> ...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
[ 12.280360] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
[ 12.291606] PCI: not using MMCONFIG
[ 12.873676] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000)
[ 12.893266] PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] reserved in ACPI motherboard resources or EFI
[ 12.903601] PCI: MMCONFIG for 0000 [bus00-7f] at [mem 0x80000000-0x87ffffff] (base 0x80000000) (size reduced!)
[ 13.385616] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended configuration space under this bridge
[ 14.115617] acpi PNP0A03:01: fail to add MMCONFIG information, can't access extended configuration space under this bridge
[ 17.969639] acpi PNP0A08:02: fail to add MMCONFIG information, can't access extended configuration space under this bridge
[ 18.298640] acpi PNP0A08:03: fail to add MMCONFIG information, can't access extended configuration space under this bridge

The EDAC driver works with this patch applied.

Tested-by: Tony Luck <tony.luck@xxxxxxxxx>

-Tony