On Fri, Jul 29, 2011 at 12:32 AM, Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxx> wrote: > I noticed that at 79896cf42f Linus changed the function from insert_resource() > to request_resource() (and later evolved into request_resource_conflict()) and > he explained the reason. So, in the NIC's case, the problem is that in > pci_claim_resource() the function pci_find_parent_resource() returns the root > (0x0-0xffffff) rather than the MSC PCI I/O (0x1000-0xffffff). This seems like the real problem: PCI has the wrong idea of the resources available on bus 00. The pci_bus->resource[0] for bus 00 points to ioport_resource (the default put there by pci_create_bus()), when it should point to to msc_io_resource instead. Some architectures fill in the pci_bus->resource[] array directly for host bridges (for examples, try 'grep -r "resource\[0\] = " arch/'). On x86 and ia64, we use pci_bus_remove_resources() and pci_bus_add_resource(), and I'd prefer that style for new code because it hides some ugly implementation details. I'm a little puzzled that we don't see this problem on more architectures. The grep above only found a few arches that update the root bus resources. I would expect most of the ones it didn't find to be broken the same way Malta is. Bjorn
