Re: [PATCH v3 2/8] ACPI: property: Tie data nodes to acpi handles

["Rafael J. Wysocki" <rafael@kernel.org>]

On Wed, May 25, 2022 at 3:01 PM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> ACPICA allows associating additional information (i.e. pointers with
> specific tag) to acpi_handles. The acpi_device's are associated to
> acpi_handle's in acpi_tie_acpi_dev() in scan.c, do the same here for the
> _DSD data nodes.
>
> This allows direct data node references in properties, implemented later on
> in the series.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/acpi/property.c | 42 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
> index bc9a645f8bb77..f8c83ee6c8d59 100644
> --- a/drivers/acpi/property.c
> +++ b/drivers/acpi/property.c
> @@ -340,6 +340,43 @@ acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
>         return props;
>  }
>
> +static void acpi_nondev_subnode_tag(acpi_handle handle, void *context)
> +{
> +}
> +
> +static void acpi_untie_nondev_subnodes(struct acpi_device_data *data)
> +{
> +       struct acpi_data_node *dn;
> +
> +       list_for_each_entry(dn, &data->subnodes, sibling) {
> +               acpi_detach_data(dn->handle, acpi_nondev_subnode_tag);
> +
> +               acpi_untie_nondev_subnodes(&dn->data);
> +       }
> +}
> +
> +static int acpi_tie_nondev_subnodes(struct acpi_device_data *data)
> +{
> +       struct acpi_data_node *dn;
> +
> +       list_for_each_entry(dn, &data->subnodes, sibling) {
> +               acpi_status status;
> +               int ret;
> +
> +               status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn);
> +               if (ACPI_FAILURE(status)) {
> +                       acpi_handle_err(dn->handle, "Can't tag data node\n");
> +                       return 0;
> +               }
> +
> +               ret = acpi_tie_nondev_subnodes(&dn->data);
> +               if (ret)
> +                       return ret;

Is it actually possible that this returns anything different from 0?

> +       }
> +
> +       return 0;
> +}
> +
>  static bool acpi_extract_properties(const union acpi_object *desc,
>                                     struct acpi_device_data *data)
>  {
> @@ -419,7 +456,9 @@ void acpi_init_properties(struct acpi_device *adev)
>                                         &adev->data, acpi_fwnode_handle(adev)))
>                 adev->data.pointer = buf.pointer;
>
> -       if (!adev->data.pointer) {
> +       if (!adev->data.pointer ||
> +           acpi_tie_nondev_subnodes(&adev->data) < 0) {
> +               acpi_untie_nondev_subnodes(&adev->data);
>                 acpi_handle_debug(adev->handle, "Invalid _DSD data, skipping\n");
>                 ACPI_FREE(buf.pointer);
>         }
> @@ -462,6 +501,7 @@ static void acpi_destroy_nondev_subnodes(struct list_head *list)
>
>  void acpi_free_properties(struct acpi_device *adev)
>  {
> +       acpi_untie_nondev_subnodes(&adev->data);
>         acpi_destroy_nondev_subnodes(&adev->data.subnodes);
>         ACPI_FREE((void *)adev->data.pointer);
>         adev->data.of_compatible = NULL;
> --
> 2.30.2
>