On Wed, 8 Nov 2006, Matthew Wilcox wrote: > > On Wed, Nov 08, 2006 at 08:39:44AM +0100, Andi Kleen wrote: > > ACPI knows the number of busses. > > But what if the number of busses increases later, eg by hotplugging > a card with a PCI-PCI bridge on it? Or does it know the number of > busses which can be supported by this machine's MMCONFIG region? ACPI will give the maximum number. However, in this case, the correct thing to do (always _has_ been) is to not use ACPI for _anything_, but just read the base and the size of the MMCONFIG region from the hardware itself. Anyway, I do not consider this a regression. MMCONFIG has _never_ worked reliably. It has always been a case of "we can make it work on some machines by making it break on others". Linus
