Add device to hierarchy before calling the driver's probe() function; this

way everything remains consistent if the probe() ends up creating child
devices.

src/core/device.c

  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <string.h>
 #include <gpxe/list.h>
 #include <gpxe/tables.h>
 #include <gpxe/device.h>
 static LIST_HEAD ( devices );
 
 /**
- * Register a root device
+ * Probe a root device
  *
  * @v rootdev		Root device
  * @ret rc		Return status code
- *
- * Calls the root device driver's probe() method, and adds it to the
- * list of registered root devices if successful.
  */
-static int register_rootdev ( struct root_device *rootdev ) {
+static int rootdev_probe ( struct root_device *rootdev ) {
 	int rc;
 
-	DBG ( "Registering %s root bus\n", rootdev->name );
-
-	if ( ( rc = rootdev->driver->probe ( rootdev ) ) != 0 )
+	DBG ( "Adding %s root bus\n", rootdev->name );
+	if ( ( rc = rootdev->driver->probe ( rootdev ) ) != 0 ) {
+		DBG ( "Failed to add %s root bus: %s\n",
+		      rootdev->name, strerror ( rc ) );
 		return rc;
+	}
 
-	list_add ( &rootdev->dev.siblings, &devices );
 	return 0;
 }
 
 /**
- * Unregister a root device
+ * Remove a root device
  *
  * @v rootdev		Root device
  */
-static void unregister_rootdev ( struct root_device *rootdev ) {
+static void rootdev_remove ( struct root_device *rootdev ) {
 	rootdev->driver->remove ( rootdev );
-	list_del ( &rootdev->dev.siblings );
-	DBG ( "Unregistered %s root bus\n", rootdev->name );
+	DBG ( "Removed %s root bus\n", rootdev->name );
 }
 
 /**
  */
 int probe_devices ( void ) {
 	struct root_device *rootdev;
+	int rc;
 
 	for ( rootdev = root_devices; rootdev < root_devices_end; rootdev++ ) {
-		register_rootdev ( rootdev );
+		list_add ( &rootdev->dev.siblings, &devices );
+		INIT_LIST_HEAD ( &rootdev->dev.children );
+		if ( ( rc = rootdev_probe ( rootdev ) ) != 0 )
+			list_del ( &rootdev->dev.siblings );
 	}
 	return 0;
 }
 	struct root_device *tmp;
 
 	list_for_each_entry_safe ( rootdev, tmp, &devices, dev.siblings ) {
-		unregister_rootdev ( rootdev );
+		rootdev_remove ( rootdev );
+		list_del ( &rootdev->dev.siblings );
 	}
 }

src/drivers/bus/pci.c

 }
 
 /**
- * Register PCI device
+ * Probe a PCI device
  *
  * @v pci		PCI device
  * @ret rc		Return status code
  *
  * Searches for a driver for the PCI device.  If a driver is found,
- * its probe() routine is called, and the device is added to the
- * device hierarchy.
+ * its probe() routine is called.
  */
-static int register_pcidev ( struct pci_device *pci ) {
+static int pci_probe ( struct pci_device *pci ) {
 	struct pci_driver *driver;
 	struct pci_device_id *id;
 	unsigned int i;
 	int rc;
 
-	DBG ( "Registering PCI device %02x:%02x.%x (%04x:%04x mem %lx "
-	      "io %lx irq %d)\n", pci->bus, PCI_SLOT ( pci->devfn ),
+	DBG ( "Adding PCI device %02x:%02x.%x (%04x:%04x mem %lx io %lx "
+	      "irq %d)\n", pci->bus, PCI_SLOT ( pci->devfn ),
 	      PCI_FUNC ( pci->devfn ), pci->vendor, pci->device,
 	      pci->membase, pci->ioaddr, pci->irq );
 
 				DBG ( "......probe failed\n" );
 				continue;
 			}
-			list_add ( &pci->dev.siblings,
-				   &pci->dev.parent->children );
 			return 0;
 		}
 	}
 }
 
 /**
- * Unregister a PCI device
+ * Remove a PCI device
  *
  * @v pci		PCI device
- *
- * Calls the device's driver's remove() routine, and removes the
- * device from the device hierarchy.
  */
-static void unregister_pcidev ( struct pci_device *pci ) {
+static void pci_remove ( struct pci_device *pci ) {
 	pci->driver->remove ( pci );
-	list_del ( &pci->dev.siblings );
-	DBG ( "Unregistered PCI device %02x:%02x.%x\n", pci->bus,
+	DBG ( "Removed PCI device %02x:%02x.%x\n", pci->bus,
 	      PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ) );
 }
 
 			pci_read_config_byte ( pci, PCI_INTERRUPT_LINE,
 					       &pci->irq );
 			pci_read_bases ( pci );
-			INIT_LIST_HEAD ( &pci->dev.children );
+
+			/* Add to device hierarchy */
 			pci->dev.parent = &rootdev->dev;
+			list_add ( &pci->dev.siblings, &rootdev->dev.children);
+			INIT_LIST_HEAD ( &pci->dev.children );
 			
 			/* Look for a driver */
-			if ( register_pcidev ( pci ) == 0 ) {
+			if ( pci_probe ( pci ) == 0 ) {
 				/* pcidev registered, we can drop our ref */
 				pci = NULL;
 			} else {
 				/* Not registered; re-use struct pci_device */
+				list_del ( &pci->dev.siblings );
 			}
 		}
 	}
 
 	list_for_each_entry_safe ( pci, tmp, &rootdev->dev.children,
 				   dev.siblings ) {
-		unregister_pcidev ( pci );
+		pci_remove ( pci );
+		list_del ( &pci->dev.siblings );
 		free ( pci );
 	}
 }
 struct root_device pci_root_device __root_device = {
 	.name = "PCI",
 	.driver = &pci_root_driver,
-	.dev = {
-		.children = LIST_HEAD_INIT ( pci_root_device.dev.children ),
-	},
 };