Re: [RFC PATCH v3 4/9] software_node: Add support for fwnode_graph*() family of functions

[Sakari Ailus]

Hi Daniel, Heikki,

Thanks for the patch.

On Mon, Oct 19, 2020 at 11:58:58PM +0100, Daniel Scally wrote:
> From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> 
> This implements the remaining .graph_* callbacks in the
> fwnode operations vector for the software nodes. That makes
> the fwnode_graph*() functions available in the drivers also
> when software nodes are used.
> 
> The implementation tries to mimic the "OF graph" as much as
> possible, but there is no support for the "reg" device
> property. The ports will need to have the index in their
> name which starts with "port" (for example "port0", "port1",
> ...) and endpoints will use the index of the software node
> that is given to them during creation. The port nodes can
> also be grouped under a specially named "ports" subnode,
> just like in DT, if necessary.
> 
> The remote-endpoints are reference properties under the
> endpoint nodes that are named "remote-endpoint". 
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> Co-developed-by: Daniel Scally <djrscally@xxxxxxxxx>
> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
> ---
> changes in v3:
> 	- removed software_node_device_is_available
> 	- moved the change to software_node_get_next_child to a separate
> 	patch
> 	- switched to use fwnode_handle_put() in graph_get_next_endpoint()
> 	instead of software_node_put()
> 
> changes in v2:
> 	- added software_node_device_is_available
> 	- altered software_node_get_next_child to get references
> 	- altered software_node_get_next_endpoint to release references
> 	to ports and avoid passing invalid combinations of swnodes to
> 	software_node_get_next_child
> 	- altered swnode_graph_find_next_port to release port rather than
> 	old
>  drivers/base/swnode.c | 120 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 119 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 741149b90..3732530ce 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -536,6 +536,120 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
>  	return 0;
>  }
>  
> +static struct fwnode_handle *
> +swnode_graph_find_next_port(const struct fwnode_handle *parent,
> +			    struct fwnode_handle *port)
> +{
> +	struct fwnode_handle *old = port;
> +
> +	while ((port = software_node_get_next_child(parent, old))) {

software_node_get_next_child() doesn't drop the reference of the old child
nor gets a reference to the returned node. Should it?

The function to get a named child node does.

It'd be nice if this was aligned. Or am I missing something?

This isn't really a comment on this patch though.

-- 
Kind regards,

Sakari Ailus