Re: [PATCH 2/2] dtc: Remove a deleted node or property from the tree

[Herve Codina <herve.codina@bootlin.com>]

Hi Simon,

On Mon, 26 Oct 2026 11:35:20 -0600
Simon Glass <sjg@chromium.org> wrote:

> Deleting a node or property only flags it as deleted, leaving it in
> place. If a later section adds it again, merge_nodes() finds the flagged
> entry and revives it where it was, along with its subnodes, which come
> back in their old order before any new ones. So deleting a node in
> order to redefine it does not give the order which the source shows.
> 
> Unlink a node or property from its parent when deleting it, so that
> adding it again creates a new entry after the existing ones. Nothing
> deleted then stays in the tree while parsing, so merge_nodes() has
> nothing to revive and can skip deleted entries like everything else.
> 
> Leave the node's next_sibling alone, since fixup_omit_unused_nodes()
> deletes nodes while walking over their siblings.
> 
> Note that this changes the output of existing dts files. When a dts
> deletes a node or property and then defines it again, the new definition
> now comes after its siblings instead of taking the old one's place, and
> its subnodes come in the order of the new definition alone.

Yes, makes sense.

> 
> This is the better behaviour because:
> 
> - Deleting is how a dts says to start again. A dts which wants to keep a
>   node's place can override the node without deleting it, since merging
>   already updates a node in place
> - Node order can matter. In issue 174, U-Boot's binman builds an image
>   from a node which is deleted and defined again, yet the image comes
>   out in the old order. The only workaround is to define the nodes in
>   the wanted order before including the file which defines them
> - It matches the previous patch, in which a node deleted and defined
>   again within a section, or deleted in the first section and defined
>   by a later one, already comes out where the new definition is
> 
> Closes: https://github.com/dgibson/dtc/issues/174
> Assisted-by: Claude:claude-opus-5-5
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---

LGTM.

Reviewed-by: Herve Codina <herve.codina@bootlin.com>

Best regards,
Hervé