Re: [patch] Make MMCONFIG space (extended PCI config space) a driver opt-in issue

Jeff Garzik
2007-12-24T07:31:34Z

Linus Torvalds wrote:
> (For example: I have three machines that I know have working MMCONF. On
> only one of theose does Linux actually even enable MMCONF accesses,
> because on the two other ones the BIOSes do the crazy "put it in some
> space that is reserved by PnP crap later", so we actually refuse to touch
> it. So at least in my limited environment, we hardly get any MMCONFIG test
> coverage, exactly because we have to be so totally anal about not enabling
> it early, because we cannot guarantee that it's not clashing with anything
> else).

Definitely. So, two questions:

What's the preferred way to deal with the desire to view extended config
space with "lspci -vvvxxx"?

Right now, we enable mmconfig for the bus/domain range requested by the
BIOS [heh, so by implication many early BIOSen stomp themselves].

Is there a path for hw vendors, after passing 1,001 anal checks, to
maintain the current behavior as it exists today in
arch/x86/pci/mmconfig_{32,64}.c?

Jeff