Index: usb_hub_acpi.c
===================================================================
--- usb_hub_acpi.c	(revision 349179)
+++ usb_hub_acpi.c	(working copy)
@@ -247,9 +247,10 @@
 	device_t grand;
 	ACPI_HANDLE gah;
 
+	*ah = NULL;
+
 	grand = device_get_parent(device_get_parent(dev));
 	if ((gah = acpi_get_handle(grand)) == NULL) {
-		*ah = NULL;
 		return AE_ERROR;
 	}
 	return AcpiWalkNamespace(ACPI_TYPE_DEVICE, gah, 1,
@@ -293,6 +294,9 @@
 	ACPI_HANDLE ah;
 	ACPI_STATUS status;
 
+	if(acpi_disabled("usb")){
+		return ENXIO;
+	}
 	status = acpi_uhub_find_rh(dev, &ah);
 	if (ACPI_SUCCESS(status)
 	    && ah != NULL
@@ -308,7 +312,7 @@
 {
 	ACPI_HANDLE ah = acpi_get_handle(dev);
 
-	if (ah && (uhub_probe(dev) <= 0)) {
+	if (!acpi_disabled("usb") && ah && (uhub_probe(dev) <= 0)) {
 		/*success prior than non - acpi hub*/
 		    return (BUS_PROBE_DEFAULT + 1);
 	}
@@ -335,7 +339,6 @@
 	sc->nports = uh->nports;
 	sc->porthandle = malloc(sizeof(ACPI_HANDLE) * uh->nports,
 	    M_USBDEV, M_WAITOK | M_ZERO);
-	acpi_uhub_find_rh(dev, &devhandle);
 	acpi_usb_hub_port_probe(dev, devhandle);
 
 	return 0;