Re: [PATCH 5/8] PCI: add generic device into pci_host_bridge struct

Yinghai Lu
2012-02-27T22:55:26Z

On Mon, Feb 27, 2012 at 2:24 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>>
>> for every bus will have ->bridge, and that is device pointer. to  pci
>> bridge dev.
>>
>> for root bus, there is not pci bridge for that. So create_root_bus
>> allocate local dummy one.
>>
>> that dummy device will be bus->dev's parent.
>>
>> Now pci_host_bridge is added, and it is allocated, so just put the
>> struct device into that pci_host_bridge.
>>
>> and use pci_host_bridge->dev as parent of root bus->dev's parent.
>
> What's the device passed in to pci_create_root_bus()?  Why is that
> different than the root bus dev's parent?

ia64 and x86 doesn't pass that.

arch/ia64/pci/pci.c: pbus = pci_create_root_bus(NULL, bus,
&pci_root_ops, controller,
arch/powerpc/kernel/pci-common.c: bus =
pci_create_root_bus(hose->parent, hose->first_busno,
arch/sparc/kernel/pci.c: bus = pci_create_root_bus(parent,
pbm->pci_first_busno, pbm->pci_ops,
arch/x86/pci/acpi.c: bus = pci_create_root_bus(NULL,
busnum, &pci_root_ops, sd,
drivers/parisc/dino.c: dino_dev->hba.hba_bus = bus =
pci_create_root_bus(&dev->dev,
drivers/parisc/lba_pci.c: pci_create_root_bus(&dev->dev,
lba_dev->hba.bus_num.start,

sparc, powerpc, parisc have their local ...

so local hose etc's dev ---> allocated dev ---> root bus's dev

this patch change to

local hose etc's dev ---> allocated host bridge's dev ---> root bus's dev