In commit 80376c3fc2c38fdd453 in 2010 we added a workaround for some qbus buses not being connected to qdev devices -- if the bus has no parent object then we register a reset function which resets the bus on system reset (and unregister it when the bus is unparented).
Nearly a decade later, we have now no buses in the tree which are created with non-NULL parents, so we can remove the workaround and instead just assert that if the bus has a NULL parent then it is the main system bus. (The absence of other parentless buses was confirmed by code inspection of all the callsites of qbus_create() and qbus_create_inplace() and cross-checked by 'make check'.) Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> Reviewed-by: Markus Armbruster <arm...@redhat.com> --- v1->v2: clean up also the bus_unparent() code --- hw/core/bus.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/hw/core/bus.c b/hw/core/bus.c index e09843f6abe..b8839c7268d 100644 --- a/hw/core/bus.c +++ b/hw/core/bus.c @@ -96,10 +96,9 @@ static void qbus_realize(BusState *bus, DeviceState *parent, const char *name) bus->parent->num_child_bus++; object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus), NULL); object_unref(OBJECT(bus)); - } else if (bus != sysbus_get_default()) { - /* TODO: once all bus devices are qdevified, - only reset handler for main_system_bus should be registered here. */ - qemu_register_reset(qbus_reset_all_fn, bus); + } else { + /* The only bus without a parent is the main system bus */ + assert(bus == sysbus_get_default()); } } @@ -108,18 +107,16 @@ static void bus_unparent(Object *obj) BusState *bus = BUS(obj); BusChild *kid; + /* Only the main system bus has no parent, and that bus is never freed */ + assert(bus->parent); + while ((kid = QTAILQ_FIRST(&bus->children)) != NULL) { DeviceState *dev = kid->child; object_unparent(OBJECT(dev)); } - if (bus->parent) { - QLIST_REMOVE(bus, sibling); - bus->parent->num_child_bus--; - bus->parent = NULL; - } else { - assert(bus != sysbus_get_default()); /* main_system_bus is never freed */ - qemu_unregister_reset(qbus_reset_all_fn, bus); - } + QLIST_REMOVE(bus, sibling); + bus->parent->num_child_bus--; + bus->parent = NULL; } void qbus_create_inplace(void *bus, size_t size, const char *typename, -- 2.20.1