On Sat, Oct 25, 2008 at 9:25 AM, Tom Sylla <[EMAIL PROTECTED]> wrote:
> > Hopefully it is clear now how things can move like that. The Opterons > won't move. It is possible with HT that other devices may exist on > higher bus numbers without a bridge (real or fake) from bus 0. It is > weird, and non-legacy compatible, so it should not happen with NB and > SB devices. There are exceptions, though, when we connect our nc > FPGAs, and put them at bus 20, we have no bridge in config space > connecting them to bus 0. By default, the linux kernel will not find > them (it does a normal PCI scan, looking for bridges, subordinates, > etc). We must advertise the non-contiguous PCI busses in an ACPI table > for Linux and Windows to "see" the higher busses that are not bridged > to bus 0. (there are some other ways to force the linux kernel to find > the devices, but the ACPI method works for all the current OSes we've > tried). The point is that making the PCI busses discontiguous is > "weird", and makes you jump through other hoops to play well with > OSes. linux kernel will do some legacy check from irq_routes_tables..... when acpi is disabled... YH
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