[PATCH] CPCI hotplug: fix resource assignment

Here is a patch against the CPCI hotplug core to fix up PCI resource
assignment such that things will actually work when a hot inserted
device is enabled.  I mentioned this patch to you way back in April at
ELC, but am only now out from under things enough to clean it up and
submit it.  I've basically cribbed the corresponding code from
shpchp_pci.c, so there are no big surprises.  If it's still possible, I
wouldn't mind this going into 2.6.18, but it wouldn't be the end of the
world if it went into 2.6.19.
Signed-off-by: Scott Murray <scottm@somanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/hotplug/cpci_hotplug_pci.c

@@ -254,8 +254,8 @@ int cpci_led_off(struct slot* slot)
 
 int cpci_configure_slot(struct slot* slot)
 {
-	unsigned char busnr;
-	struct pci_bus *child;
+	struct pci_bus *parent;
+	int fn;
 
 	dbg("%s - enter", __FUNCTION__);
 
@@ -276,23 +276,53 @@ int cpci_configure_slot(struct slot* slot)
 		 */
 		n = pci_scan_slot(slot->bus, slot->devfn);
 		dbg("%s: pci_scan_slot returned %d", __FUNCTION__, n);
-		if (n > 0)
-			pci_bus_add_devices(slot->bus);
 		slot->dev = pci_get_slot(slot->bus, slot->devfn);
 		if (slot->dev == NULL) {
 			err("Could not find PCI device for slot %02x", slot->number);
-			return 1;
+			return -ENODEV;
 		}
 	}
+	parent = slot->dev->bus;
+
+	for (fn = 0; fn < 8; fn++) {
+		struct pci_dev *dev;
+
+		dev = pci_get_slot(parent, PCI_DEVFN(PCI_SLOT(slot->devfn), fn));
+		if (!dev)
+			continue;
+		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
+		    (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)) {
+			/* Find an unused bus number for the new bridge */
+			struct pci_bus *child;
+			unsigned char busnr, start = parent->secondary;
+			unsigned char end = parent->subordinate;
 
-	if (slot->dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
-		pci_read_config_byte(slot->dev, PCI_SECONDARY_BUS, &busnr);
-		child = pci_add_new_bus(slot->dev->bus, slot->dev, busnr);
-		pci_do_scan_bus(child);
+			for (busnr = start; busnr <= end; busnr++) {
+				if (!pci_find_bus(pci_domain_nr(parent),
+						  busnr))
+					break;
+			}
+			if (busnr >= end) {
+				err("No free bus for hot-added bridge\n");
+				pci_dev_put(dev);
+				continue;
+			}
+			child = pci_add_new_bus(parent, dev, busnr);
+			if (!child) {
+				err("Cannot add new bus for %s\n",
+				    pci_name(dev));
+				pci_dev_put(dev);
+				continue;
+			}
+			child->subordinate = pci_do_scan_bus(child);
 			pci_bus_size_bridges(child);
 		}
+		pci_dev_put(dev);
+	}
 
-	pci_bus_assign_resources(slot->dev->bus);
+	pci_bus_assign_resources(parent);
+	pci_bus_add_devices(parent);
+	pci_enable_bridges(parent);
 
 	dbg("%s - exit", __FUNCTION__);
 	return 0;