On Mon, Feb 27, 2012 at 3:55 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > On Mon, Feb 27, 2012 at 2:24 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> 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 Why do we have a separate dev for the hose and the root bus's dev? The hose *is* a PCI host bridge. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
