Re: [PATCH 07/10] dt-bindings: mtd: Ensure partition node properties are documented

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: "Rob Herring (Arm)" <robh@kernel.org>
Cc: "Richard Weinberger" <richard@nod.at>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Brian Norris" <computersforpeace@gmail.com>,
	"Kamal Dasu" <kdasu.kdev@gmail.com>,
	"William Zhang" <william.zhang@broadcom.com>,
	"Nick Terrell" <terrelln@fb.com>,
	"David Sterba" <dsterba@suse.com>,
	"Rafał Miłecki" <rafal@milecki.pl>,
	"Simon Glass" <sjg@chromium.org>,
	"Linus Walleij" <linusw@kernel.org>,
	"Ulf Hansson" <ulf.hansson@linaro.org>,
	"Marcus Folkesson" <marcus.folkesson@gmail.com>,
	"Tony Lindgren" <tony@atomide.com>,
	"Roger Quadros" <rogerq@kernel.org>,
	"Hauke Mehrtens" <hauke@hauke-m.de>,
	linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org
Subject: Re: [PATCH 07/10] dt-bindings: mtd: Ensure partition node properties are documented
Date: Fri, 09 Jan 2026 10:02:07 +0100	[thread overview]
Message-ID: <87fr8fxipc.fsf@bootlin.com> (raw)
In-Reply-To: <20260108-dt-mtd-partitions-v1-7-124a53ce6279@kernel.org> (Rob Herring's message of "Thu, 08 Jan 2026 11:53:16 -0600")

Hello Rob,

On 08/01/2026 at 11:53:16 -06, "Rob Herring (Arm)" <robh@kernel.org> wrote:

> Partition nodes without a compatible have no restrictions on additional
> properties. Fix this by ensuring 'unevaluatedProperties' is set when
> there's no compatible property. If there is a compatible property, then
> there should be a specific schema for it which will enforce
> 'unevaluatedProperties'.
>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---

Overall thank you very much for this series, I've been sruggling while
defining these and your approach seems very relevant. I am fine with all
the patches in this series, but will wait a bit for others to make a bit
of feedback.

[...]

> +$defs:
> +  partition-node:
> +    type: object
> +    if:
> +      not:
> +        required: [ compatible ]
> +    then:
> +      $ref: '#'
> +      unevaluatedProperties: false
> +    else:
> +      $ref: '#'

This, however, is total blackmagic to me. Would you mind explaining what

      $ref: '#'

indicates? Is this a placeholder indicating "a reference must be given?

Also I do not understand the final else case, what is it covering?

Thanks for the little explanation (or you can give me a pointer to some
relevant doc I could read).

Thanks,
Miquèl