Re: [Qemu-devel] [PATCH 3/6] hw/arm: Use sysbus_init_child_obj for correct reference counting

[Philippe Mathieu-Daudé]

On 7/29/19 3:03 PM, Peter Maydell wrote:
> On Mon, 1 Jul 2019 at 13:31, Philippe Mathieu-Daudé <address@hidden> wrote:
>>
>> As explained in commit aff39be0ed97:
>>
>>   Both functions, object_initialize() and object_property_add_child()
>>   increase the reference counter of the new object, so one of the
>>   references has to be dropped afterwards to get the reference
>>   counting right. Otherwise the child object will not be properly
>>   cleaned up when the parent gets destroyed.
>>   Thus let's use now object_initialize_child() instead to get the
>>   reference counting here right.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
>> ---
>>  hw/arm/exynos4_boards.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/arm/exynos4_boards.c b/hw/arm/exynos4_boards.c
>> index ac0b0dc2a9..5dd53d2a23 100644
>> --- a/hw/arm/exynos4_boards.c
>> +++ b/hw/arm/exynos4_boards.c
>> @@ -129,8 +129,8 @@ exynos4_boards_init_common(MachineState *machine,
>>      exynos4_boards_init_ram(s, get_system_memory(),
>>                              exynos4_board_ram_size[board_type]);
>>
>> -    object_initialize(&s->soc, sizeof(s->soc), TYPE_EXYNOS4210_SOC);
>> -    qdev_set_parent_bus(DEVICE(&s->soc), sysbus_get_default());
>> +    sysbus_init_child_obj(OBJECT(machine), "soc",
>> +                          &s->soc, sizeof(s->soc), TYPE_EXYNOS4210_SOC);
>>      object_property_set_bool(OBJECT(&s->soc), true, "realized",
>>                               &error_fatal);
> 
> I suspect the code change here is correct but it doesn't seem
> to match the commit message -- the old code is not calling
> object_property_add_child() at all, and the new code does not
> call object_initialize_child()...

OK, will improve, thanks!