On Wed, Mar 8, 2023 at 3:17 AM Qun-Wei Lin <qun-wei.lin@xxxxxxxxxxxx> wrote:
>
> The overlay fragment is a special case where some properties are not
> present in the overlay source file, but in the base file.
>
> example:
> +-----------------------------+--------------------+
> | base.dts | overlay.dts |
> +-----------------------------+--------------------+
> | /dts-v1/; | /dts-v1/; |
> | | /plugin/; |
> | /{ | |
> | parent: test { | &parent { |
> | #address-cells = <1>; | child@0 { |
> | #size-cells = <0>; | reg = <0x0>; |
> | }; | }; |
> | }; | }; |
> +-----------------------------+--------------------+
>
> It will cause the following false alarms when compiling the overlay dts.
>
> 1. /fragment@0/__overlay__: Character '_' not recommended in node name
> 2. /fragment@0/__overlay__: Relying on default #address-cells value
> 3. /fragment@0/__overlay__: Relying on default #size-cells value
> 4. /fragment@0/__overlay__:reg: property has invalid length (4 bytes)
> (#address-cells == 2, #size-cells == 1)
>
> This workaround will fix them by skip checking for node named __overlay__.
>
> Signed-off-by: Qun-Wei Lin <qun-wei.lin@xxxxxxxxxxxx>
> ---
> V1 -> V2:
> - Add is_overlay_node() helper
> - Skip anything starting with "__" in check_node_name_chars_strict()
>
> checks.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Though I do wonder if as a matter of policy on overlay structure, if
we should require an overlay to have the parent node with
#address-cells/#size-cells. In the end that would be duplicated data,
but without it there's no way to parse and validate reg/ranges in an
unapplied overlay. That's just one example issue in being able to
validate overlays.
Rob
