Re: [PATCH net-next] net: dsa: mv88e6xxx: fix unreleased fwnode_handle in setup_port()

From: Andrew Lunn
Date: Sun Oct 20 2024 - 10:47:34 EST


On Sun, Oct 20, 2024 at 12:21:07AM +0200, Javier Carrasco wrote:
> On 19/10/2024 23:59, Andrew Lunn wrote:
> > On Sat, Oct 19, 2024 at 10:16:49PM +0200, Javier Carrasco wrote:
> >> 'ports_fwnode' is initialized via device_get_named_child_node(), which
> >> requires a call to fwnode_handle_put() when the variable is no longer
> >> required to avoid leaking memory.
> >>
> >> Add the missing fwnode_handle_put() after 'ports_fwnode' has been used
> >> and is no longer required.
> >
> > As you point out, the handle is obtained with
> > device_get_named_child_node(). It seems odd to use a fwnode_ function
> > not a device_ function to release the handle. Is there a device_
> > function?
> >
> > Andrew
>
>
> Hi Andrew,
>
> device_get_named_child_node() receives a pointer to a *device*, and
> returns a child node (a pointer to an *fwnode_handle*). That is what has
> to be released, and therefore fwnode_handle_put() is the right one.
>
> Note that device_get_named_child_node() documents how to release the
> fwnode pointer:
>
> "The caller is responsible for calling fwnode_handle_put() on the
> returned fwnode pointer."

O.K. I just don't like asymmetric APIs. They often lead to bugs, just
look wrong, and make reviewers ask questions...

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

Andrew