Re: [PATCH v2 02/13] include/hw: document the device_class_set_parent_* fns

[Mark Cave-Ayland]

On 18/04/2023 17:21, Alex Bennée wrote:

> These are useful functions for when you want proper inheritance of
> functionality across realize/unrealize calls.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   include/hw/qdev-core.h | 27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
>
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index d4bbc30c92..b1d194b561 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -795,9 +795,36 @@ void device_class_set_props(DeviceClass *dc, Property 
> *props);
>   void device_class_set_parent_reset(DeviceClass *dc,
>                                      DeviceReset dev_reset,
>                                      DeviceReset *parent_reset);
> +
> +/**
> + * device_class_set_parent_realize(): set up for chaining realize fns
> + * @dc: The device class
> + * @dev_realize: the device realize function
> + * @parent_realize: somewhere to save the parents realize function
> + *
> + * This is intended to be used when the new realize function will
> + * eventually call its parent realization function during creation.
> + * This requires storing the function call somewhere (usually in the
> + * instance structure) so you can eventually call:

I think this should be the class structure, since it is the only possible location 
for the parent realize() function to exist given that these functions are called from 
the .class_init function.

> + *   my_dev->parent_realize(dev, errp);
> + */
>   void device_class_set_parent_realize(DeviceClass *dc,
>                                        DeviceRealize dev_realize,
>                                        DeviceRealize *parent_realize);
> +
> +
> +/**
> + * device_class_set_parent_unrealize(): set up for chaining unrealize fns
> + * @dc: The device class
> + * @dev_unrealize: the device realize function
> + * @parent_unrealize: somewhere to save the parents unrealize function
> + *
> + * This is intended to be used when the new unrealize function will
> + * eventually call its parent unrealization function during the
> + * unrealize phase. This requires storing the function call somewhere
> + * (usually in the instance structure) so you can eventually call:
> + *   my_dev->parent_unrealize(dev);

And same here of course.

> + */
>   void device_class_set_parent_unrealize(DeviceClass *dc,
>                                          DeviceUnrealize dev_unrealize,
>                                          DeviceUnrealize *parent_unrealize);


ATB,

Mark.