Re: [RFC PATCH v3 1/9] software_node: Add helper function to unregister arrays of software_nodes ordered parent to child

Sakari Ailus
2020-10-20T10:05:22Z

Hi Daniel, Andy,

On Mon, Oct 19, 2020 at 11:58:55PM +0100, Daniel Scally wrote:
> Software nodes that are children of another software node should be
> unregistered before their parent. To allow easy unregistering of an array
> of software_nodes ordered parent to child, add a helper function to loop
> over and unregister nodes in such an array in reverse order.
>
> Suggested-by: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Daniel Scally <djrscally@gmail.com>
> ---
> Changes in v3:
> - patch introduced.
>
> drivers/base/swnode.c | 21 +++++++++++++++++++++
> include/linux/property.h | 1 +
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 010828fc7..f01b1cc61 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -727,6 +727,27 @@ void software_node_unregister_nodes(const struct software_node *nodes)
> }
> EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
>
> +/**
> + * software_node_unregister_nodes_reverse - Unregister an array of software
> + * nodes in reverse order.
> + * @nodes: Array of software nodes to be unregistered.
> + *
> + * NOTE: The same warning applies as with software_node_unregister_nodes.
> + * Unless you are _sure_ that the array of nodes is ordered parent to child
> + * it is wiser to remove them individually in the correct order.

Could the default order in software_node_unregister_nodes() be reversed
instead? There are no users so this should be easy to change.

Doing this only one way may require enforcing the registration order in
software_node_register_nodes(), but the end result would be safer.

What do you think?

--
Regards,

Sakari Ailus