diff --git a/hw/openpic.c b/hw/openpic.c
index 68af9c1de1..42db59daa7 100644
--- a/hw/openpic.c
+++ b/hw/openpic.c
@@ -1202,8 +1202,6 @@ qemu_irq *openpic_init (PCIBus *bus, int *pmem_index, int nb_cpus,
     if (bus) {
         opp = (openpic_t *)pci_register_device(bus, "OpenPIC", sizeof(openpic_t),
                                                -1, NULL, NULL);
-        if (opp == NULL)
-            return NULL;
         pci_conf = opp->pci_dev.config;
         pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_IBM);
         pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_IBM_OPENPIC2);
diff --git a/hw/pci.c b/hw/pci.c
index 6864339c27..5b3461cd66 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -499,10 +499,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
             if (!bus->devices[devfn])
                 goto found;
         }
-        return NULL;
+        hw_error("PCI: no devfn available for %s, all in use\n", name);
     found: ;
     } else if (bus->devices[devfn]) {
-        return NULL;
+        hw_error("PCI: devfn %d not available for %s, in use by %s\n", devfn,
+                 name, bus->devices[devfn]->name);
     }
     pci_dev->bus = bus;
     pci_dev->devfn = devfn;
@@ -1273,7 +1274,6 @@ static int pci_qdev_init(DeviceState *qdev, DeviceInfo *base)
     pci_dev = do_pci_register_device(pci_dev, bus, base->name, devfn,
                                      info->config_read, info->config_write,
                                      info->header_type);
-    assert(pci_dev);
     rc = info->init(pci_dev);
     if (rc != 0)
         return rc;