[PATCH] acpi bridge hotadd: Prevent duplicate bus numbers when scanning PCI bridge

[karo-tx-linux.git] / drivers / pci / probe.c

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3dc00f0ca8a0e2b0f2374edc9b092048d700e68c..6186f4d7b1192fc65bd0a7d9fde2357c883f0cc9 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -411,7 +411,7 @@ 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;
+       u32 buses, i;
        u16 bctl;
 
        pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
@@ -470,6 +470,10 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max
                /* Clear errors */
                pci_write_config_word(dev, PCI_STATUS, 0xffff);
 
+               /* Prevent assigning a bus number that already exists.
+                * This can happen when a bridge is hot-plugged */
+               if (pci_find_bus(pci_domain_nr(bus), max+1))
+                       return max;
                child = pci_alloc_child_bus(bus, dev, ++max);
                buses = (buses & 0xff000000)
                      | ((unsigned int)(child->primary)     <<  0)
@@ -501,7 +505,11 @@ 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.
                         */
-                       max += CARDBUS_RESERVE_BUSNR;
+                       for (i=0; i<CARDBUS_RESERVE_BUSNR; i++)
+                               if (pci_find_bus(pci_domain_nr(bus),
+                                                       max+i+1))
+                                       break;
+                       max += i;
                }
                /*
                 * Set the subordinate bus number to its real value.