diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
index da88cb3352..f434596e8f 100644
--- a/hw/pci-host/prep.c
+++ b/hw/pci-host/prep.c
@@ -326,6 +326,7 @@ static void raven_realize(PCIDevice *d, Error **errp)
             }
         }
         if (bios_size < 0 || bios_size > BIOS_SIZE) {
+            /* FIXME should error_setg() */
             hw_error("qemu: could not load bios image '%s'\n", s->bios_name);
         }
         g_free(filename);
@@ -355,8 +356,9 @@ static void raven_class_init(ObjectClass *klass, void *data)
     dc->desc = "PReP Host Bridge - Motorola Raven";
     dc->vmsd = &vmstate_raven;
     /*
-     * PCI-facing part of the host bridge, not usable without the
-     * host-facing part, which can't be device_add'ed, yet.
+     * Reason: PCI-facing part of the host bridge, not usable without
+     * the host-facing part, which can't be device_add'ed, yet.
+     * Reason: realize() method uses hw_error().
      */
     dc->cannot_instantiate_with_device_add_yet = true;
 }