pci_scan_child_bus can (potentially) return a bus number higher than the subordinate value of the child bus. Possible reasons are that bus numbers are reserved for SR-IOV or for CardBus (SR-IOV is done without checks and the CardBus checks are sketchy at best).
We clamp the returned value to the actual subordinate value and print a warning if too many bus numbers are reserved. Signed-off-by: Andreas Noever <[email protected]> --- drivers/pci/probe.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 90d5c48..74bc644 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -805,10 +805,13 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) } cmax = pci_scan_child_bus(child); - if (cmax > max) - max = cmax; - if (child->busn_res.end > max) - max = child->busn_res.end; + if (cmax > subordinate) + dev_warn(&dev->dev, + "bridge has subordinate %02x but max busn %02x\n", + subordinate, cmax); + /* subordinate should equal child->busn_res.end */ + if (subordinate > max) + max = subordinate; } else { /* * We need to assign a number to this bus which we always -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
