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Message-ID: <71ae3799-4668-891c-c32d-d36da655d56d@linaro.org>
Date:   Fri, 23 Jun 2023 11:52:25 +0100
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Subject: Re: [PATCH v2 2/2] arm64: dts: qcom: msm8939-samsung-a7: Add initial
 dts
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To:     "Lin, Meng-Bo" <linmengbo0689@protonmail.com>
Cc:     agross@kernel.org, andersson@kernel.org, conor+dt@kernel.org,
        devicetree@vger.kernel.org, konrad.dybcio@linaro.org,
        krzysztof.kozlowski+dt@linaro.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, nikita@trvn.ru, robh+dt@kernel.org,
        stephan@gerhold.net, ~postmarketos/upstreaming@lists.sr.ht
References: <20230623100135.5269-1-linmengbo0689@protonmail.com>
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 <20230623104647.5501-1-linmengbo0689@protonmail.com>
From:   Bryan O'Donoghue <bryan.odonoghue@linaro.org>
In-Reply-To: <20230623104647.5501-1-linmengbo0689@protonmail.com>
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On 23/06/2023 11:47, Lin, Meng-Bo wrote:
> Hi Bryan,
> 
> On Friday, June 23rd, 2023 at 10:27 AM, Bryan O'Donoghue <bryan.odonoghue@linaro.org> wrote:
> 
>>> +++ b/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
>>> @@ -0,0 +1,495 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +
>>> +/dts-v1/;
>>> +
>>> +#include "msm8939-pm8916.dtsi"
>>> +
>>> +#include <dt-bindings/gpio/gpio.h>
>>> +#include <dt-bindings/input/input.h>
>>> +#include <dt-bindings/interrupt-controller/irq.h>
>>> +
>>> +/ {
>>> + model = "Samsung Galaxy A7 (2015)";
>>> + compatible = "samsung,a7", "qcom,msm8939";
>>> + chassis-type = "handset";
>>
>>
>> Will the downstream bootloader accept this dts without
>>
>> // This is used by the bootloader to find the correct DTB
>> qcom,msm-id = <239 0>;
>>
>> qcom,board-id = <0xEF08FF1 1>;
>>
>>
>> ?
>>
>> https://github.com/msm8916-mainline/lk2nd/blob/master/dts/msm8916/msm8939-samsung-r01.dts#L10
>>
> 
> Similar to A3 and A5, and the other msm8916 devices, with lk2nd,
> "qcom,msm-id" or "qcom,board-id" are not required in mainline to boot
> this dts.
> If I understand correctly, lk2nd will attempt to boot an image with any
> qcdt appended.
> 
> https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/qcom/msm8916-samsung-a3u-eur.dts
> https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/qcom/msm8916-samsung-a5u-eur.dts

I understand.

IMO the upstream DTS should work without depending on lk2nd.

I'd add the board and msm id to the DTS for that reason.

If not then I'd put a comment into the DTS explaining the dependency.

For preference the upstream dts should *just work* as much as possible 
without requiring churning of bootloader.

---
bod