Re: [PATCH v2 04/16] ACPI: property: Return present device nodes only on fwnode interface

Laurent Pinchart
2025-09-24T09:58:02Z

On Wed, Sep 24, 2025 at 10:45:50AM +0300, Sakari Ailus wrote:
> fwnode_graph_get_next_subnode() may return fwnode backed by ACPI device
> nodes and there has been no check these devices are present in the system,
> unlike there has been on fwnode OF backend. In order to provide consistent
> behaviour towards callers, add a check for device presence by introducing
> a new function acpi_get_next_present_subnode(), used as the
> get_next_child_node() fwnode operation that also checks device node
> presence.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
> drivers/acpi/property.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
> index 5438592dc136..01f3880ffcce 100644
> --- a/drivers/acpi/property.c
> +++ b/drivers/acpi/property.c
> @@ -1319,6 +1319,26 @@ acpi_get_next_subnode(const struct fwnode_handle *fwnode,
> return NULL;
> }
>
> +/**

/*

as the function is static ?

> + * acpi_get_next_present_subnode - Return the next present child node handle for a fwnode
> + * @fwnode: Firmware node to find the next child node for.
> + * @child: Handle to one of the device's child nodes or a null handle.

A blank line here would be nice.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> + * Like acpi_get_next_subnode(), but the device nodes returned by
> + * acpi_get_next_present_subnode() are guaranteed to be present.
> + * Returns: The next sub-node fwnode handle.
> + */
> +static struct fwnode_handle *
> +acpi_get_next_present_subnode(const struct fwnode_handle *fwnode,
> + struct fwnode_handle *child)
> +{
> + do {
> + child = acpi_get_next_subnode(fwnode, child);
> + } while (is_acpi_device_node(child) &&
> + !acpi_device_is_present(to_acpi_device_node(child)));
> +
> + return child;
> +}
> +
> /**
> * acpi_node_get_parent - Return parent fwnode of this fwnode
> * @fwnode: Firmware node whose parent to get
> @@ -1664,7 +1684,7 @@ static int acpi_fwnode_irq_get(const struct fwnode_handle *fwnode,
> .property_read_string_array = \
> acpi_fwnode_property_read_string_array, \
> .get_parent = acpi_node_get_parent, \
> - .get_next_child_node = acpi_get_next_subnode, \
> + .get_next_child_node = acpi_get_next_present_subnode, \
> .get_named_child_node = acpi_fwnode_get_named_child_node, \
> .get_name = acpi_fwnode_get_name, \
> .get_name_prefix = acpi_fwnode_get_name_prefix, \

--
Regards,

Laurent Pinchart