Re: [Qemu-arm] [Qemu-devel] [PATCH 5/6] hw/dma/xilinx_axi: Use object_initialize_child for correct ref. counting

[Alistair Francis]

On Tue, Jul 2, 2019 at 10:00 AM Philippe Mathieu-Daudé
<address@hidden> wrote:
>
> On 7/2/19 6:18 PM, Alistair Francis wrote:
> > On Mon, Jul 1, 2019 at 5:32 AM 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>
> >
> > Reviewed-by: Alistair Francis <address@hidden>
> >
> > Alistair
> >
> >> ---
> >>  hw/dma/xilinx_axidma.c | 16 ++++++++--------
> >>  1 file changed, 8 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> >> index 921be178d9..91f5ec587f 100644
> >> --- a/hw/dma/xilinx_axidma.c
> >> +++ b/hw/dma/xilinx_axidma.c
> >> @@ -563,14 +563,14 @@ static void xilinx_axidma_init(Object *obj)
> >>      XilinxAXIDMA *s = XILINX_AXI_DMA(obj);
> >>      SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> >>
> >> -    object_initialize(&s->rx_data_dev, sizeof(s->rx_data_dev),
> >> -                      TYPE_XILINX_AXI_DMA_DATA_STREAM);
> >> -    object_initialize(&s->rx_control_dev, sizeof(s->rx_control_dev),
> >> -                      TYPE_XILINX_AXI_DMA_CONTROL_STREAM);
> >> -    object_property_add_child(OBJECT(s), "axistream-connected-target",
> >> -                              (Object *)&s->rx_data_dev, &error_abort);
> >> -    object_property_add_child(OBJECT(s), 
> >> "axistream-control-connected-target",
> >> -                              (Object *)&s->rx_control_dev, &error_abort);
> >> +    object_initialize_child(OBJECT(s), "axistream-connected-target",
> >> +                            &s->rx_data_dev, sizeof(s->rx_data_dev),
> >> +                            TYPE_XILINX_AXI_ENET_DATA_STREAM, 
> >> &error_abort,
> >> +                            NULL);
> >> +    object_initialize_child(OBJECT(s), 
> >> "axistream-control-connected-target",
> >> +                            &s->rx_control_dev, sizeof(s->rx_control_dev),
> >> +                            TYPE_XILINX_AXI_ENET_CONTROL_STREAM, 
> >> &error_abort,
> >> +                            NULL);
> >>
> >>      sysbus_init_irq(sbd, &s->streams[0].irq);
> >>      sysbus_init_irq(sbd, &s->streams[1].irq);
> >> --
> >> 2.20.1
>
> As GCC suggested, this patch requires this snippet squashed:
>
> -- >8 --
> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> @@ -565,11 +565,11 @@ static void xilinx_axidma_init(Object *obj)
>
>      object_initialize_child(OBJECT(s), "axistream-connected-target",
>                              &s->rx_data_dev, sizeof(s->rx_data_dev),
> -                            TYPE_XILINX_AXI_ENET_DATA_STREAM, &error_abort,
> +                            TYPE_XILINX_AXI_DMA_DATA_STREAM, &error_abort,
>                              NULL);
>      object_initialize_child(OBJECT(s),
> "axistream-control-connected-target",
>                              &s->rx_control_dev, sizeof(s->rx_control_dev),
> -                            TYPE_XILINX_AXI_ENET_CONTROL_STREAM,
> &error_abort,
> +                            TYPE_XILINX_AXI_DMA_CONTROL_STREAM,
> &error_abort,
>                              NULL);
>
>      sysbus_init_irq(sbd, &s->streams[0].irq);
> ---

Ah I missed that

>
> Since it was commented in reply to the cover, I assume your R-b stands
> with the snippet applied.

Yeah it does.

Alistair

>
> Thanks for reviewing,
>
> Phil.