Re: [PATCH v1 12/18] driver core: Add fw_devlink_parse_fwtree()

Rafael J. Wysocki
2020-11-16T16:26:06Z

On Thu, Nov 5, 2020 at 12:24 AM Saravana Kannan <saravanak@google.com> wrote:
>
> This function is a wrapper around fwnode_operations.add_links().
>
> This function parses each node in a fwnode tree and create fwnode links
> for each of those nodes. The information for creating the fwnode links
> (the supplier and consumer fwnode) is obtained by parsing the properties
> in each of the fwnodes.
>
> This function also ensures that no fwnode is parsed more than once by
> marking the fwnodes as parsed.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
> drivers/base/core.c | 19 +++++++++++++++++++
> include/linux/fwnode.h | 3 +++
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 4a0907574646..ee28d8c7ee85 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1543,6 +1543,25 @@ static bool fw_devlink_is_permissive(void)
> return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY;
> }
>
> +static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
> +{
> + if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
> + return;

Why is the flag needed?

Duplicate links won't be created anyway and it doesn't cause the tree
walk to be terminated.

> +
> + fwnode_call_int_op(fwnode, add_links, NULL);
> + fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
> +}
> +
> +static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
> +{
> + struct fwnode_handle *child = NULL;
> +
> + fw_devlink_parse_fwnode(fwnode);
> +
> + while ((child = fwnode_get_next_available_child_node(fwnode, child)))

I'd prefer

for (child = NULL; child; child =
fwnode_get_next_available_child_node(fwnode, child))

> + fw_devlink_parse_fwtree(child);
> +}
> +
> static void fw_devlink_link_device(struct device *dev)
> {
> int fw_ret;
> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> index ec02e1e939cc..9aaf9e4f3994 100644
> --- a/include/linux/fwnode.h
> +++ b/include/linux/fwnode.h
> @@ -15,12 +15,15 @@
> struct fwnode_operations;
> struct device;
>

Description here, please.

> +#define FWNODE_FLAG_LINKS_ADDED BIT(0)
> +
> struct fwnode_handle {
> struct fwnode_handle *secondary;
> const struct fwnode_operations *ops;
> struct device *dev;
> struct list_head suppliers;
> struct list_head consumers;
> + u32 flags;

That's a bit wasteful. Maybe u8 would suffice for the time being?

> };
>
> struct fwnode_link {
> --
> 2.29.1.341.ge80a0c044ae-goog
>