Re: [PATCH] of: property: fw_devlink: Fixup behaviour when 'node_not_dev' is set

[Saravana Kannan <saravanak@google.com>]

On Thu, Sep 2, 2021 at 2:02 AM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> In the struct supplier_bindings the member 'node_not_dev' is described as
> "The consumer node containing the property is never a device.", but that is
> inconsistent with the behaviour of the code in of_link_property(), as it
> calls of_get_compat_node() that starts parsing for a compatible property
> from the node it gets passed to it. The proper behaviour is to start at the
> node's parent, so let's do that.
>
> While at it, let's take the opportunity to update the description of the
> 'node_not_dev' flag, as to clarify its purpose.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Reviewed-by: Saravana Kannan <saravanak@google.com>

-Saravana

> ---
>  drivers/of/property.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 6c028632f425..a94d007be416 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1075,6 +1075,17 @@ static struct device_node *of_get_compat_node(struct device_node *np)
>         return np;
>  }
>
> +static struct device_node *of_get_compat_node_parent(struct device_node *np)
> +{
> +       struct device_node *parent, *node;
> +
> +       parent = of_get_parent(np);
> +       node = of_get_compat_node(parent);
> +       of_node_put(parent);
> +
> +       return node;
> +}
> +
>  /**
>   * of_link_to_phandle - Add fwnode link to supplier from supplier phandle
>   * @con_np: consumer device tree node
> @@ -1249,7 +1260,9 @@ static struct device_node *parse_##fname(struct device_node *np,       \
>   * @parse_prop.index: For properties holding a list of phandles, this is the
>   *                   index into the list
>   * @optional: Describes whether a supplier is mandatory or not
> - * @node_not_dev: The consumer node containing the property is never a device.
> + * @node_not_dev: The consumer node containing the property is never converted
> + *               to a struct device. Instead, parse ancestor nodes for the
> + *               compatible property to find a node corresponding to a device.
>   *
>   * Returns:
>   * parse_prop() return values are
> @@ -1416,7 +1429,7 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
>                         struct device_node *con_dev_np;
>
>                         con_dev_np = s->node_not_dev
> -                                       ? of_get_compat_node(con_np)
> +                                       ? of_get_compat_node_parent(con_np)
>                                         : of_node_get(con_np);
>                         matched = true;
>                         i++;
> --
> 2.25.1
>