1 files changed, 37 insertions, 2 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 00ba6a03dca5..3c9834d80850 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -433,7 +433,7 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
 {
         struct pci_bus *child;
         int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
-        u32 buses, i;
+        u32 buses, i, j = 0;
         u16 bctl;
 
         pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
@@ -543,10 +543,29 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
                          * as cards with a PCI-to-PCI bridge can be
                          * inserted later.
                          */
-                        for (i=0; i<CARDBUS_RESERVE_BUSNR; i++)
+                        for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
+                                struct pci_bus *parent = bus;
                                 if (pci_find_bus(pci_domain_nr(bus),
                                                         max+i+1))
                                         break;
+                                while (parent->parent) {
+                                        if ((!pcibios_assign_all_busses()) &&
+                                            (parent->subordinate > max) &&
+                                            (parent->subordinate <= max+i)) {
+                                                j = 1;
+                                        }
+                                        parent = parent->parent;
+                                }
+                                if (j) {
+                                        /*
+                                         * Often, there are two cardbus bridges
+                                         * -- try to leave one valid bus number
+                                         * for each one.
+                                         */
+                                        i /= 2;
+                                        break;
+                                }
+                        }
                         max += i;
                         pci_fixup_parent_subordinate_busnr(child, max);
                 }
@@ -561,6 +580,22 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
 
         sprintf(child->name, (is_cardbus ? "PCI CardBus #%02x" : "PCI Bus #%02x"), child->number);
 
+        while (bus->parent) {
+                if ((child->subordinate > bus->subordinate) ||
+                    (child->number > bus->subordinate) ||
+                    (child->number < bus->number) ||
+                    (child->subordinate < bus->number)) {
+                        printk(KERN_WARNING "PCI: Bus #%02x (-#%02x) may be "
+                               "hidden behind%s bridge #%02x (-#%02x)%s\n",
+                               child->number, child->subordinate,
+                               bus->self->transparent ? " transparent" : " ",
+                               bus->number, bus->subordinate,
+                               pcibios_assign_all_busses() ? " " :
+                               " (try 'pci=assign-busses')");
+                }
+                bus = bus->parent;
+        }
+
         return max;
 }