Re: [PATCH v3 08/11] hw/sparc/sun4m: Realize DMA controller before accessing it

[Peter Maydell]

On Thu, 8 Feb 2024 at 18:14, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> We should not wire IRQs on unrealized device.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  hw/sparc/sun4m.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c
> index e782c8ec7a..d52e6a7213 100644
> --- a/hw/sparc/sun4m.c
> +++ b/hw/sparc/sun4m.c
> @@ -312,13 +312,11 @@ static void *sparc32_dma_init(hwaddr dma_base,
>      dma = qdev_new(TYPE_SPARC32_DMA);
>      espdma = SPARC32_ESPDMA_DEVICE(object_resolve_path_component(
>                                     OBJECT(dma), "espdma"));
> -    sysbus_connect_irq(SYS_BUS_DEVICE(espdma), 0, espdma_irq);
>
>      esp = SYSBUS_ESP(object_resolve_path_component(OBJECT(espdma), "esp"));
>
>      ledma = SPARC32_LEDMA_DEVICE(object_resolve_path_component(
>                                   OBJECT(dma), "ledma"));
> -    sysbus_connect_irq(SYS_BUS_DEVICE(ledma), 0, ledma_irq);
>
>      lance = SYSBUS_PCNET(object_resolve_path_component(
>                           OBJECT(ledma), "lance"));
> @@ -332,6 +330,11 @@ static void *sparc32_dma_init(hwaddr dma_base,
>      }
>
>      sysbus_realize_and_unref(SYS_BUS_DEVICE(dma), &error_fatal);
> +
> +    sysbus_connect_irq(SYS_BUS_DEVICE(espdma), 0, espdma_irq);
> +
> +    sysbus_connect_irq(SYS_BUS_DEVICE(ledma), 0, ledma_irq);
> +

(This confused me briefly until I realised that this function
is reaching into the dma device to find child objects to connect
the IRQs to. Perhaps it would be nicer if the wrapping 'dma' object
passed through those IRQs to avoid that.)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM