Re: [PATCH 1/2] dt-bindings: display/panel: Add Innolux EJ030NA

From: Paul Cercueil <paul@crapouillou.net>
To: Rob Herring <robh@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, list@opendingux.net,
	Christophe Branchereau <cbranchereau@gmail.com>
Subject: Re: [PATCH 1/2] dt-bindings: display/panel: Add Innolux EJ030NA
Date: Wed, 14 Jul 2021 21:40:46 +0100	[thread overview]
Message-ID: <YF59WQ.VTZ17PPSJ9I02@crapouillou.net> (raw)
In-Reply-To: <20210714203013.GA3287208@robh.at.kernel.org>

Hi Rob,

Le mer., juil. 14 2021 at 14:30:13 -0600, Rob Herring <robh@kernel.org> 
a écrit :
> On Sat, Jul 10, 2021 at 11:21:56AM +0100, Paul Cercueil wrote:
>> 
>>  [...]
>> 
>>  > >  I am not sure; the doc states that this (additionalProperties:
>>  > > false) "can't
>>  > >  be used in case where another schema is referenced", which is 
>> the
>>  > > case here,
>>  > >  as we include "panel-common.yaml".
>>  >
>>  > This DT schema already list all relevant properties like:
>>  >
>>  > 	backlight: true
>>  >
>>  > So "additionalProperties: false" tells that no other properties 
>> are
>>  > allowed other than the listed properties.
>>  >
>>  > To my best understanding unevaluatedProperties: false is less 
>> strict and
>>  > should be used if one does not list all possilbe properties.
> 
> Right. There's some value of listing which common properties you are
> using as well.
> 
>>  > This could be the case for a panel haging below a SPI controller 
>> as in
>>  > this case. So in other words giving this some extra thought I 
>> think
>>  > unevaluatedProperties: false is OK here.
>> 
>>  A panel below a SPI controller would have all its SPI-specific 
>> properties
>>  covered by spi-controller.yaml, I believe? So maybe 
>> "additionalProperties:
>>  false" would work?
> 
> No. Because spi-controller.yaml is evaluated on the SPI host node and
> this one is evaluated on the SPI slave. There's some work to address
> this, but it means every SPI slave will have to reference a SPI device
> schema. The bigger issue here is SPI controller specific device
> properties. So for this case, we'll have to use unevaluatedProperties.

Thank you for the clarification.

Cheers,
-Paul

>> 
>>  In any case, if I use "additionalProperties: false", "make 
>> dt_binding_check"
>>  complains that my example's "spi-max-frequency" property is not 
>> covered. So
>>  maybe you are right.
>> 
>>  > So my r-b is ok if you keep it as it.
>>  >
>>  > PS. Where do you guys hang out with the downfall of freenode - 
>> somewhere
>>  > on oftc?
>> 
>>  We moved to #opendingux on Libera.
>> 
>>  Cheers,
>>  -Paul
>> 
>> 
>> 