Only create default devices when requested, avoid have the
machine implementation to modify the generic 'usb' boolean
set from command line.

Fixes: 59a0419856c ("hw/ppc/mac_newworld: simplify usb controller creation logic")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/ppc/mac_newworld.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
index 0b6e096116a..7598d42cbc2 100644
--- a/hw/ppc/mac_newworld.c
+++ b/hw/ppc/mac_newworld.c
@@ -346,7 +346,6 @@ static void ppc_core99_init(MachineState *machine)
                                     sysbus_mmio_get_region(s, 3));
     }
 
-    machine->usb |= defaults_enabled() && !machine->usb_disabled;
     has_pmu = (core99_machine->via_config != CORE99_VIA_CONFIG_CUDA);
     has_adb = (core99_machine->via_config == CORE99_VIA_CONFIG_CUDA ||
                core99_machine->via_config == CORE99_VIA_CONFIG_PMU_ADB);
@@ -427,7 +426,7 @@ static void ppc_core99_init(MachineState *machine)
 
         /* U3 needs to use USB for input because Linux doesn't support via-cuda
         on PPC64 */
-        if (!has_adb || machine_arch == ARCH_MAC99_U3) {
+        if ((!has_adb || machine_arch == ARCH_MAC99_U3) && defaults_enabled()) {
             USBBus *usb_bus;
 
             usb_bus = USB_BUS(object_resolve_type_unambiguous(TYPE_USB_BUS,
-- 
2.47.1