On Thu, Jul 28, 2011 at 5:28 AM, Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxx> wrote: > In resolving a network driver issue with the MIPS Malta platform, the root > cause was traced into pci_claim_resource(): > > MIPS System Controller's PCI I/O resources stay in 0x1000-0xffffff. When > PCI quirks start claiming resources using request_resource_conflict(), > collisions happen and -EBUSY is returned, thereby rendering the onboard AMD > PCnet32 NIC unaware of quirks' region and preventing the NIC from functioning. > For PCI quirks, PIIX4 ACPI is expected to claim 0x1000-0x103f, and PIIX4 SMB to > claim 0x1100-0x110f, both of which fall into the MSC I/O range. Certainly, we > can increase the start point of this range in arch/mips/mti-malta/malta-pci.c to > avoid the collisions. But a fix in here looks more justified, though it seems to > have a wider impact. Using insert_xxx as opposed to request_xxx will register > PCI quirks' resources as children of MSC I/O and return OK, instead of seeing > collisions which are actually resolvable. What's the collision? Can we see the dmesg log (which should have that information) and maybe the /proc/ioports contents? Did something change the order in which we claim resources, so things that used to work now cause conflicts? I think insert_resource() (where the newly-inserted resource can become the parent of something that was previously inserted) is sort of a hack, and the fact that we need it is telling us that we're doing things in the wrong order. It's nicer when we can discover and claim resources in a top-down hierarchical way. But I recognize that may not always be possible, or at least not convenient. Bjorn
