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

Jeff Garzik
2007-05-23T21:09:55Z

Jesse Barnes wrote:
> Apparently Vista will move away from using type 1 config space accesses
> though, so if we keep using it, we'll probably run into some lame board

Yep.

> that assumes you're using mmconfig at some point in the near future.
> But then again, we're often on that less tested path (e.g. with ACPI),
> so maybe that doesn't matter much.

One of the reasons why hardware vendors want to move away from
traditional accesses is to be able to use the larger config space in
PCI-Express, rather than being locked into the 256-byte legacy PCI
config space.

Several modern PCI-Express devices utilize the upper config space, but
due to legacy reasons the registers are usually ones that do not require
OS drivers to know about (like BIST stuff or diagnostic registers).

Expect that to change, as MS shakes out the bugs (or maybe we are doing
their job for them?).

Jeff