Re: [Qemu-devel] [PATCH 1/6] qdev: Make qbus_walk_children() call busfn for root bus.

[Markus Armbruster]

Please excuse my late reply.  I'm so much behind in this list, it's not
funny anymore.

I agree with Anthony, this series looks nice.  A few remarks inline.


Isaku Yamahata <address@hidden> writes:

> Make qbus_walk_children() call busfn for root bus.

Please don't repeat the subject in the body.

While I'm nit-picking about commit messages: subject is a heading, and
as such it shouldn't end in a period.

> and it fixes qbus_realize_all().

Can't see qbus_realize_all() in master; I guess it's in Anthony's tree.

> The current qbus_walk_children() doesn't call busfn for root bus.
> It cause qbus_relialize_all() to fail to call realize the system bus.

Do you mean qbus_realize_all()?

> This patch also refactor qbus_walk_children() a bit.
> Another only user of busfn, qbus_find_child_bus(), isn't affected by this.
>
> Signed-off-by: Isaku Yamahata <address@hidden>
> ---
>  hw/qdev-core.h |    2 ++
>  hw/qdev.c      |   51 ++++++++++++++++++++++++++++++---------------------
>  2 files changed, 32 insertions(+), 21 deletions(-)
>
> diff --git a/hw/qdev-core.h b/hw/qdev-core.h
> index 5fdee3a..a9b7692 100644
> --- a/hw/qdev-core.h
> +++ b/hw/qdev-core.h
> @@ -186,6 +186,8 @@ BusState *qbus_create(BusInfo *info, DeviceState *parent, 
> const char *name);
>  /* Returns > 0 if either devfn or busfn terminate walk, 0 otherwise. */
>  int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn, 
>                         qbus_walkerfn *busfn, void *opaque);
> +int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
> +                       qbus_walkerfn *busfn, void *opaque);
>  
>  DeviceState *qbus_find_child_dev(BusState *bus, const char *id);
>  BusState *qbus_find_child_bus(BusState *bus, const char *id);
> diff --git a/hw/qdev.c b/hw/qdev.c
> index a981e05..c1ba6b8 100644
> --- a/hw/qdev.c
> +++ b/hw/qdev.c
> @@ -296,33 +296,42 @@ int qbus_walk_children(BusState *bus, qdev_walkerfn 
> *devfn,
>                         qbus_walkerfn *busfn, void *opaque)
>  {
>      DeviceState *dev;
> +    int err;
> +
> +    if (busfn) {
> +        err = busfn(bus, opaque);
> +        if (err) {
> +            return err;
> +        }
> +    }
>  
>      QLIST_FOREACH(dev, &bus->children, sibling) {
> -        BusState *child;
> -        int err = 0;
> +        err = qdev_walk_children(dev, devfn, busfn, opaque);
> +        if (err < 0) {
> +            return err;
> +        }
> +    }
>  
> -        if (devfn) {
> -            err = devfn(dev, opaque);
> +    return 0;
> +}
> +
> +int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
> +                       qbus_walkerfn *busfn, void *opaque)
> +{
> +    BusState *bus;
> +    int err;
> +
> +    if (devfn) {
> +        err = devfn(dev, opaque);
> +        if (err) {
> +            return err;
>          }
> +    }
>  
> -        if (err > 0) {
> +    QLIST_FOREACH(bus, &dev->child_bus, sibling) {
> +        err = qbus_walk_children(bus, devfn, busfn, opaque);
> +        if (err < 0) {
>              return err;
> -        } else if (err == 0) {
> -            QLIST_FOREACH(child, &dev->child_bus, sibling) {
> -                if (busfn) {
> -                    err = busfn(child, opaque);
> -                    if (err > 0) {
> -                        return err;
> -                    }
> -                }
> -
> -                if (err == 0) {
> -                    err = qbus_walk_children(child, devfn, busfn, opaque);
> -                    if (err > 0) {
> -                        return err;
> -                    }
> -                }
> -            }
>          }
>      }

Isn't it funny that functions that work on a qdev sub-trees always come
in pairs?  qdev_foo() and qbus_foo().  That's because of the split
between device and bus nodes.