Re: [PATCH v7 1/3] dt-bindings: mtd: Add Loongson-1 NAND Controller

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Keguang Zhang <keguang.zhang@gmail.com>
Cc: Keguang Zhang via B4 Relay
	<devnull+keguang.zhang.gmail.com@kernel.org>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-mips@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v7 1/3] dt-bindings: mtd: Add Loongson-1 NAND Controller
Date: Thu, 6 Jun 2024 23:33:44 +0200	[thread overview]
Message-ID: <20240606233344.4e268c04@xps-13> (raw)
In-Reply-To: <CAJhJPsW9gVe2F1qvxvOkQUX_K1BsK5q_1XjT0u2+QH2gRMNqXA@mail.gmail.com>

Hi,

> > > > > +properties:
> > > > > +  compatible:
> > > > > +    oneOf:
> > > > > +      - const: loongson,ls1b-nfc  
> > > >
> > > > What is the rationale behind this choice? Seems like the b variant has
> > > > two possible implementations and should always be preceded by a more
> > > > specific compatible.
> > > >
> > > > As there is currently no description of this controller upstream, I
> > > > would not care too much about any out-of-tree description and directly
> > > > go for a clean description.
> > > >  
> > > Excuse me, should I add a description for this property?  
> >
> > No, description is not needed. But you are allowing the
> > "loongson,ls1b-nfc" compatible alone, which I think is not relevant,
> > unless you convince me it is :-)
> >  
> "loongson,ls1b-nfc" itself is a specific implementation.
> I was suggested to set up a fallback before.
> https://lore.kernel.org/all/20231007-untapped-masses-01f80b7c13c7@spud/
> Then "loongson,ls1b-nfc" became the fallback.

You cannot allow 'the fallback', alone. But this is what you do above.
Below description is fine. Just don't allow the ls1b-nfc compatible
alone.

Thanks,
Miquèl