Re: [Qemu-devel] [PATCH 3/5] PXB: convert to realize()

[Marcel Apfelbaum <marcel@redhat.com>]

On 12/22/2015 11:16 AM, Cao jin wrote:
>
>
> On 12/22/2015 03:34 PM, Marcel Apfelbaum wrote:
>> On 12/22/2015 05:58 AM, Cao jin wrote:
>>>
>>>
>>> On 12/21/2015 11:49 PM, Paolo Bonzini wrote:
>>>>
>>>>
>>>> On 20/12/2015 12:38, Cao jin wrote:
>>>>>>>
>>>>>>> +    object_unref(OBJECT(ds));
>>>>>>> +    object_unref(OBJECT(bds));
>>>>>>> +    object_unref(OBJECT(bus));
>>>>>>
>>>>>> I think these should be object_unparent, not unref.
>>>>>>
>>>>>
>>>>> But, it seems these 3 objects isn`t added as a child-property via
>>>>> object_property_add_child() during creation, so OBJECT(ds)->parent(so
>>>>> does the other 2) will be NULL, and so object_unparent will do nothing?
>>>>
>>>> qdev_init_nofail adds them (qdev_init_nofail -> object_property_set_bool
>>>> -> device_set_realized -> object_property_add_child).
>>>>
>>>> If you haven't reached qdev_init_nofail, you should indeed unref ds and
>>>> bds instead.  However, the bus should be unparented because pci_bus_new
>>>> makes it a child of ds (pci_bus_new -> qbus_create -> qbus_realize ->
>>>> object_property_add_child).
>>>>
>>>
>>> Yes...that`s true.
>>>
>>> and @Marcel, I think maybe this is final decision?
>>
>>
>> I say add a debug trace line before pxb_register_bus (or use the debugger)
>> and check ds->parent, bds->parent and bus->parent.
>>
>
> uh..sorry I don`t get it, what does the debug trace line/use debugger mean?
>
>> Run the qemu with -device pxb,bus=80,... and for every one that its parent
>> is not null add unparent. :)
>
> don`t get it too, could you detail it?


Sure, just add something like:

     fprintf(stderr, "ds parent: %p, bus parent... ", ds->parent ...)

Compile and run QEMU with a pxb device:
     <qemu-bin>  -device pxb,bus=80,...

And look for which object has a parent :)

Thanks,
Marcel

>
>>
>> Thanks,
>> Marcel
>>
>>
>>
>>
>>>
>>>> Paolo
>>>>
>>>>
>>>> .
>>>>
>>>
>>
>>
>>
>>
>