Re: [PATCH RFC v3 2/9] dt-bindings: board: Introduce board-id

Rob Herring
2024-05-21T21:32:31Z

On Tue, May 21, 2024 at 2:25 PM Conor Dooley <conor@kernel.org> wrote:
>
> On Tue, May 21, 2024 at 08:21:45PM +0100, Conor Dooley wrote:
> > On Tue, May 21, 2024 at 11:37:59AM -0700, Elliot Berman wrote:
> > > Device manufcturers frequently ship multiple boards or SKUs under a
> > > single softwre package. These software packages ship multiple devicetree
> > > blobs and require some mechanims to pick the correct DTB for the boards
> > > that use the software package.
> >
> > Okay, you've got the problem statement here, nice.
> >
> > > This patch introduces a common language
> > > for adding board identifiers to devicetrees.
> >
> > But then a completely useless remainder of the commit message.
> > I open this patch, see the regexes, say "wtf", look at the commit
> > message and there is absolutely no explanation of what these properties
> > are for. That's quite frankly just not good enough - even for an RFC.
> >
> > >
> > > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> > > ---
> > > .../devicetree/bindings/board/board-id.yaml | 24 ++++++++++++++++++++++
> > > 1 file changed, 24 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/board/board-id.yaml b/Documentation/devicetree/bindings/board/board-id.yaml
> > > new file mode 100644
> > > index 000000000000..99514aef9718
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/board/board-id.yaml
> > > @@ -0,0 +1,24 @@
> > > +# SPDX-License-Identifier: BSD-2-Clause
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/board/board-id.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: board identifiers
> > > +description: Common property for board-id subnode
> >
> > s/property/properties/
> >
> > > +
> > > +maintainers:
> > > + - Elliot Berman <quic_eberman@quicinc.com>
> > > +
> > > +properties:
> > > + $nodename:
> > > + const: '/'
> > > + board-id:
> > > + type: object
> > > + patternProperties:
> > > + "^.*(?!_str)$":
> >
> > Does this regex even work? Take "foo_str" as an example - doesn't "^.*"
> > consume all of the string, leaving the negative lookahead with nothing
> > to object to? I didn't properly test this with an example and the dt
> > tooling, but I lazily threw it into regex101 and both the python and
> > emcascript versions agree with me. Did you test this?
> >
> > And while I am here, no underscores in property names please. And if
> > "str" means string, I suggest not saving 3 characters.
> >
> > > + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> > > + "^.*_str$":
> > > + $ref: /schemas/types.yaml#/definitions/string-array
> >
> > Why do we even need two methods? Commit message tells me nothing and
> > there's no description at all... Why do we need regexes here, rather
> > than explicitly defined properties? Your commit message should explain
> > the justification for that and the property descriptions (as comments if
> > needs be for patternProperties) should explain why this is intended to
> > be used.
> >
> > How is anyone supposed to look at this binding and understand how it
> > should be used?
>
> Also, please do not CC private mailing lists on your postings, I do not
> want to get spammed by linaro's mailman :(

boot-architecture is not private[0]. It is where EBBR gets discussed
amongst other things. This came up in a thread there[1].

Rob

[0] https://lists.linaro.org/mailman3/lists/boot-architecture.lists.linaro.org/
[1] https://lists.linaro.org/archives/list/boot-architecture@lists.linaro.org/thread/DZCZSOCRH5BN7YOXEL2OQKSDIY7DCW2M/