Merge branch 'pci/scan-bridge' into next

* pci/scan-bridge:
  PCI: Don't scan random busses in pci_scan_bridge()
  PCI: Check for child busses which use more bus numbers than allocated
  PCI: Remove pci_fixup_parent_subordinate_busnr()
  PCI: Make sure bus number resources stay within their parents bounds
  PCI: Use request_resource_conflict() instead of insert_ for bus numbers
  PCI: Assign CardBus bus number only during the second pass
  PCI: Clarify the "scan anyway" comment in pci_scan_bridge()
  PCI: Increment max correctly in pci_scan_bridge()

1 files changed, 29 insertions, 47 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6e34498ec9f0..509494381a7a 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -731,22 +731,6 @@ struct pci_bus *__ref pci_add_new_bus(struct pci_bus *parent, struct pci_dev *de
         return child;
 }
 
-static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
-{
-        struct pci_bus *parent = child->parent;
-
-        /* Attempts to fix that up are really dangerous unless
-           we're going to re-assign all bus numbers. */
-        if (!pcibios_assign_all_busses())
-                return;
-
-        while (parent->parent && parent->busn_res.end < max) {
-                parent->busn_res.end = max;
-                pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
-                parent = parent->parent;
-        }
-}
-
 /*
  * If it's a bridge, configure it and scan the bus behind it.
  * For CardBus bridges, we don't scan behind as the devices will
@@ -782,7 +766,7 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
         /* Check if setup is sensible at all */
         if (!pass &&
             (primary != bus->number || secondary <= bus->number ||
-             secondary > subordinate)) {
+             secondary > subordinate || subordinate > bus->busn_res.end)) {
                 dev_info(&dev->dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n",
                          secondary, subordinate);
                 broken = 1;
@@ -805,11 +789,10 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
                         goto out;
 
                 /*
-                 * If we already got to this bus through a different bridge,
-                 * don't re-add it. This can happen with the i450NX chipset.
-                 *
-                 * However, we continue to descend down the hierarchy and
-                 * scan remaining child buses.
+                 * The bus might already exist for two reasons: Either we are
+                 * rescanning the bus or the bus is reachable through more than
+                 * one bridge. The second case can happen with the i450NX
+                 * chipset.
                  */
                 child = pci_find_bus(pci_domain_nr(bus), secondary);
                 if (!child) {
@@ -822,17 +805,19 @@ 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
                  * do in the second pass.
                  */
                 if (!pass) {
-                        if (pcibios_assign_all_busses() || broken)
+                        if (pcibios_assign_all_busses() || broken || is_cardbus)
                                 /* Temporarily disable forwarding of the
                                    configuration cycles on all bridges in
                                    this bus segment to avoid possible
@@ -844,19 +829,25 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
                         goto out;
                 }
 
+                if (max >= bus->busn_res.end) {
+                        dev_warn(&dev->dev, "can't allocate child bus %02x from %pR\n",
+                                 max, &bus->busn_res);
+                        goto out;
+                }
+
                 /* 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, so in
-                 * this case we only re-scan this bus. */
+                /* The bus will already exist if we are rescanning */
                 child = pci_find_bus(pci_domain_nr(bus), max+1);
                 if (!child) {
-                        child = pci_add_new_bus(bus, dev, ++max);
+                        child = pci_add_new_bus(bus, dev, max+1);
                         if (!child)
                                 goto out;
-                        pci_bus_insert_busn_res(child, max, 0xff);
+                        pci_bus_insert_busn_res(child, max+1,
+                                                bus->busn_res.end);
                 }
+                max++;
                 buses = (buses & 0xff000000)
                       | ((unsigned int)(child->primary)     <<  0)
                       | ((unsigned int)(child->busn_res.start)   <<  8)
@@ -878,20 +869,7 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
 
                 if (!is_cardbus) {
                         child->bridge_ctl = bctl;
-                        /*
-                         * Adjust subordinate busnr in parent buses.
-                         * We do this before scanning for children because
-                         * some devices may not be detected if the bios
-                         * was lazy.
-                         */
-                        pci_fixup_parent_subordinate_busnr(child, max);
-                        /* Now we can scan all subordinate buses... */
                         max = pci_scan_child_bus(child);
-                        /*
-                         * now fix it up again since we have found
-                         * the real value of max.
-                         */
-                        pci_fixup_parent_subordinate_busnr(child, max);
                 } else {
                         /*
                          * For CardBus bridges, we leave 4 bus numbers
@@ -922,11 +900,15 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
                                 }
                         }
                         max += i;
-                        pci_fixup_parent_subordinate_busnr(child, max);
                 }
                 /*
                  * Set the subordinate bus number to its real value.
                  */
+                if (max > bus->busn_res.end) {
+                        dev_warn(&dev->dev, "max busn %02x is outside %pR\n",
+                                 max, &bus->busn_res);
+                        max = bus->busn_res.end;
+                }
                 pci_bus_update_busn_res_end(child, max);
                 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
         }
@@ -1835,7 +1817,7 @@ int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
                 res->flags |= IORESOURCE_PCI_FIXED;
         }
 
-        conflict = insert_resource_conflict(parent_res, res);
+        conflict = request_resource_conflict(parent_res, res);
 
         if (conflict)
                 dev_printk(KERN_DEBUG, &b->dev,