Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <6e1686d0-50f4-8681-1f15-2e4df957ebc8@kernel.org>
Date:   Mon, 28 Mar 2022 19:35:10 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH 3/5] arm64: dts: imx8mp: Enable HS400-ES
Content-Language: en-US
To:     Ahmad Fatoum <a.fatoum@pengutronix.de>,
        Adam Ford <aford173@gmail.com>
Cc:     Krzysztof Kozlowski <krzk+dt@kernel.org>,
        linux-mmc <linux-mmc@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Fabio Estevam <festevam@gmail.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Adam Ford-BE <aford@beaconembedded.com>,
        Haibo Chen <haibo.chen@nxp.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        NXP Linux Team <linux-imx@nxp.com>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        arm-soc <linux-arm-kernel@lists.infradead.org>
References: <20220327123835.28329-1-aford173@gmail.com>
 <20220327123835.28329-3-aford173@gmail.com>
 <c964bf2c-f7bf-451c-1691-02903f20c634@pengutronix.de>
 <CAHCN7xL05pBK0uK7zuE7Uq4P9Rzo6bHbJdbOt5XnQRB7Sh3msw@mail.gmail.com>
 <74e74ea8-1554-bf08-b0ea-36e77259cb18@pengutronix.de>
 <5c24c12b-3a12-1e18-9f03-2c54cad30bf9@kernel.org>
 <CAHCN7xJ28t3igV8uHWfLxJx6wWkwzojg-d0QTTZM9jdfGCbTzw@mail.gmail.com>
 <5282b39b-85d5-81d6-10d5-a45c66d4d4e9@kernel.org>
 <010b3600-81dd-f5e3-2d57-8cab8efd58f0@pengutronix.de>
 <37da40fe-6e85-af40-756b-d022fe2559aa@kernel.org>
 <e2a3e6c0-d98c-7417-31bd-5f674c9c32b4@pengutronix.de>
From:   Krzysztof Kozlowski <krzk@kernel.org>
In-Reply-To: <e2a3e6c0-d98c-7417-31bd-5f674c9c32b4@pengutronix.de>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 28/03/2022 15:42, Ahmad Fatoum wrote:
> On 28.03.22 15:14, Krzysztof Kozlowski wrote:
>> On 28/03/2022 15:07, Ahmad Fatoum wrote:
>>> On 28.03.22 14:56, Krzysztof Kozlowski wrote:
>>>> You could also add two cases:
>>>> 1. three compatibles, deprecated: True,
>>>> 2. two compatibles, without imx7d.
>>>>
>>>> Existing DTS stays with three compatibles for two years and later gets
>>>> converted to two compatibles. New DTS should use two compatibles.
>>>>
>>>> It's quite a lot of churn, but would make in the long term bindings
>>>> correct and also not break other users/projects.
>>>
>>> I don't see why we need to deprecate the old binding. New SoCs
>>> can be imx8mm-usdhc compatible from the beginning and need not
>>> care about the old binding. Existing SoCs can just remain imx7d-usdhc
>>> compatible as they are now.
>>>
>>> I don't see what the deprecation accomplishes.
>>
>> It avoids to have too many entries of imx8mm (imx8mm alone,
>> imx8mm+imx7d, imx8xx+imx8mm+imx7d).
> 
> I see. I assume use of deprecated binding will be reported on a dtbs_check?

Unfortunately no, at least not yet. :-(

> If so, the expectation is that downstream projects run dtbs_check on their
> imported Linux DT repository, see the deprecation warning and extend
> their drivers to comply with it.
> 
> Some time later upstream will remove the deprecated binding and adjust
> the device trees. This works for me.
>

Yes. Plus this gives the notice to downstream projects, to comply with
the change of DTS.

Best regards,
Krzysztof