Re: [Qemu-devel] [PATCH 6/9] pci.c: factor out while(bus) bus->next loop logic into pci_find_bus_from().

[Gerd Hoffmann <kraxel@redhat.com>]

On 10/01/09 08:28, Michael S. Tsirkin wrote:
> On Thu, Oct 01, 2009 at 12:29:34PM +0900, Isaku Yamahata wrote:
>>>> +static PCIBus *pci_find_bus_from(PCIBus *from, int bus_num)
>>>
>>> Why what is "from"? pci_find_parent_bus a better name?
>>
>> Its intention is to go down from a given parent bus
>> to find child bus of a given bus number, bus_num.
>> The current implementation arranges PCIBus in a single linked list,
>> and a single linked list doesn't represent pci bus topology well.
>> So it may find a pci bus which isn't child of a given bus.

Can we have two pci busses with the same bus number in a system?

> I won't be surprised if we need a tree to represent PCI bus topology.
> But we already have it, don't we: each bus lists devices behind it, some
> of these could be buses.

Yes, the qdev device tree has all the needed info already.

cheers,
   Gerd