Re: [Qemu-devel] [PATCH v2 2/3] audio: use object link instead ofqdev property to pass wm8750 reference

[maozy <maozhongyi@cmss.chinamobile.com>]

Hi, Philippe

On 10/12/18 5:53 PM, Philippe Mathieu-Daudé wrote:
> Hi Mao,
> 
> On 12/10/2018 10:30, Mao Zhongyi wrote:
>> According to qdev-properties.h, properties of pointer type should
>> be avoided, it seems a link type property is a good substitution.
>>
>> Cc: Jan Kiszka <jan.kiszka@web.de>
>> Cc: Peter Maydell <peter.maydell@linaro.org>
>> Cc: Gerd Hoffmann <kraxel@redhat.com>
>> To: qemu-arm@nongnu.org
>>
>> Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
>> ---
>>   hw/arm/musicpal.c          |  3 ++-
>>   hw/audio/marvell_88w8618.c | 14 ++++++--------
>>   2 files changed, 8 insertions(+), 9 deletions(-)
>>
>> diff --git a/hw/arm/musicpal.c b/hw/arm/musicpal.c
>> index 3dafb41b0b..ac266f9253 100644
>> --- a/hw/arm/musicpal.c
>> +++ b/hw/arm/musicpal.c
>> @@ -1695,7 +1695,8 @@ static void musicpal_init(MachineState *machine)
>>       wm8750_dev = i2c_create_slave(i2c, TYPE_WM8750, MP_WM_ADDR);
>>       dev = qdev_create(NULL, "mv88w8618_audio");
>>       s = SYS_BUS_DEVICE(dev);
>> -    qdev_prop_set_ptr(dev, TYPE_WM8750, wm8750_dev);
>> +    object_property_set_link(OBJECT(dev), OBJECT(wm8750_dev),
>> +                             TYPE_WM8750, NULL);
>>       qdev_init_nofail(dev);
>>       sysbus_mmio_map(s, 0, MP_AUDIO_BASE);
>>       sysbus_connect_irq(s, 0, pic[MP_AUDIO_IRQ]);
>> diff --git a/hw/audio/marvell_88w8618.c b/hw/audio/marvell_88w8618.c
>> index cf6ce6979b..baab4a3d53 100644
>> --- a/hw/audio/marvell_88w8618.c
>> +++ b/hw/audio/marvell_88w8618.c
>> @@ -15,6 +15,7 @@
>>   #include "hw/i2c/i2c.h"
>>   #include "hw/audio/wm8750.h"
>>   #include "audio/audio.h"
>> +#include "qapi/error.h"
>>   
>>   #define MP_AUDIO_SIZE           0x00001000
>>   
>> @@ -252,6 +253,11 @@ static void mv88w8618_audio_init(Object *obj)
>>       memory_region_init_io(&s->iomem, obj, &mv88w8618_audio_ops, s,
>>                             "audio", MP_AUDIO_SIZE);
>>       sysbus_init_mmio(dev, &s->iomem);
>> +
>> +    object_property_add_link(OBJECT(dev), "mv88w8618", TYPE_WM8750,
>> +                             (Object **) &s->wm,
>> +                             qdev_prop_allow_set_link_before_realize,
>> +                             0, &error_abort);
>>   }
>>   
>>   static void mv88w8618_audio_realize(DeviceState *dev, Error **errp)
>> @@ -279,11 +285,6 @@ static const VMStateDescription mv88w8618_audio_vmsd = {
>>       }
>>   };
>>   
>> -static Property mv88w8618_audio_properties[] = {
>> -    DEFINE_PROP_PTR(TYPE_WM8750, mv88w8618_audio_state, wm),
>> -    {/* end of list */},
>> -};
>> -
>>   static void mv88w8618_audio_class_init(ObjectClass *klass, void *data)
>>   {
>>       DeviceClass *dc = DEVICE_CLASS(klass);
>> @@ -291,9 +292,6 @@ static void mv88w8618_audio_class_init(ObjectClass *klass, void *data)
>>       dc->realize = mv88w8618_audio_realize;
>>       dc->reset = mv88w8618_audio_reset;
>>       dc->vmsd = &mv88w8618_audio_vmsd;
>> -    dc->props = mv88w8618_audio_properties;
>> -    /* Reason: pointer property "wm8750" */
>> -    dc->user_creatable = false;
> 
> Having a link property isn't it the same restriction?

This task can found in 
https://wiki.qemu.org/Contribute/BiteSizedTasks#Device_models

Convert qdev pointer properties (defined with DEFINE_PROP_PTR) to QOM 
links. Example: commit 873b4d3.

Thanks,
Mao

> 
>>   }
>>   
>>   static const TypeInfo mv88w8618_audio_info = {
>>
>