Re: [Qemu-devel] [PATCH 20/22] xen_backend: Convert sysbus init function to realize function

From: Peter Maydell <peter.maydell@linaro.org>
To: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>,
	Anthony PERARD <anthony.perard@citrix.com>,
	"open list:X86" <xen-devel@lists.xenproject.org>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Subject: Re: [Qemu-devel] [PATCH 20/22] xen_backend: Convert sysbus init function to realize function
Date: Tue, 20 Nov 2018 14:49:49 +0000	[thread overview]
Message-ID: <CAFEAcA92SCAar143VMkJiLGEv0kUzMBXJySN8MEd7Ze9U_rBew@mail.gmail.com> (raw)
In-Reply-To: <20181119120820.29878-21-maozhongyi@cmss.chinamobile.com>

On 19 November 2018 at 12:08, Mao Zhongyi
<maozhongyi@cmss.chinamobile.com> wrote:
> Use DeviceClass rather than SysBusDeviceClass in
> xen_sysdev_class_init().
>
> Cc: sstabellini@kernel.org
> Cc: anthony.perard@citrix.com
> Cc: xen-devel@lists.xenproject.org
>
> Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> ---
>  hw/xen/xen_backend.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
> index 9a8e8771ec..73b0ed0169 100644
> --- a/hw/xen/xen_backend.c
> +++ b/hw/xen/xen_backend.c
> @@ -809,9 +809,8 @@ static const TypeInfo xensysbus_info = {
>      }
>  };
>
> -static int xen_sysdev_init(SysBusDevice *dev)
> +static void xen_sysdev_realize(DeviceState *dev, Error **errp)
>  {
> -    return 0;
>  }
>
>  static Property xen_sysdev_properties[] = {
> @@ -821,9 +820,8 @@ static Property xen_sysdev_properties[] = {
>  static void xen_sysdev_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
> -    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
>
> -    k->init = xen_sysdev_init;
> +    dc->realize = xen_sysdev_realize;
>      dc->props = xen_sysdev_properties;
>      dc->bus_type = TYPE_XENSYSBUS;
>  }

If the realize function doesn't do anything at all, can't
we just omit it ?

thanks
-- PMM