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Message-ID: <d955f3bb-c73e-4777-b268-a8abc70788ef@quicinc.com>
Date: Tue, 19 Dec 2023 18:19:50 +0800
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Subject: Re: [PATCH v3 4/6] arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi
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To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Tengfei Fan
	<quic_tengfan@quicinc.com>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>
CC: <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20231219005007.11644-1-quic_tengfan@quicinc.com>
 <20231219005007.11644-5-quic_tengfan@quicinc.com>
 <ec730ce7-2021-4cad-97e6-0a86c6063533@linaro.org>
 <cd5a0140-295a-4f48-a378-3c2b8be0f499@quicinc.com>
 <f0f707c0-dd96-4409-bfc5-118d885933e8@linaro.org>
From: "Aiqun Yu (Maria)" <quic_aiquny@quicinc.com>
In-Reply-To: <f0f707c0-dd96-4409-bfc5-118d885933e8@linaro.org>
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On 12/19/2023 6:01 PM, Krzysztof Kozlowski wrote:
> On 19/12/2023 10:57, Aiqun Yu (Maria) wrote:
>>
>>
>> On 12/19/2023 3:02 PM, Krzysztof Kozlowski wrote:
>>> On 19/12/2023 01:50, Tengfei Fan wrote:
>>>> QCS8550 is derived from SM8550, it is mainly used in IoT scenarios.
>>>
>>> What are the differences? You need to describe the hardware, you have
>>> entire commit msg for something useful which will avoid such comments
>>> from reviewers.
>>>
>>>>
>>>> Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>
>>>> ---
>>>>    arch/arm64/boot/dts/qcom/qcs8550.dtsi | 6 ++++++
>>>>    1 file changed, 6 insertions(+)
>>>>    create mode 100644 arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>>>
>>>> diff --git a/arch/arm64/boot/dts/qcom/qcs8550.dtsi b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>>> new file mode 100644
>>>> index 000000000000..254657f46c5e
>>>> --- /dev/null
>>>> +++ b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
>>>> @@ -0,0 +1,6 @@
>>>> +// SPDX-License-Identifier: BSD-3-Clause
>>>> +/*
>>>> + * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
>>>> + */
>>>> +
>>>> +#include "sm8550.dtsi"
>>>
>>> This is a weird file. I thought qcs8550 has differences from sm8550,
>>> e.g. lack of modem, so why do you claim you have here MPSS?
>> MPSS here in qcs8550 is a GPS only MPSS.
> 
> Is it different or the same? Is the interface the same? So many
> questions and so little information. You have entire commit msg to
> explain this.
we can add all current email information into the commit message in next 
patchset.
> 
>>
>> QCS8550 will have a different firmware release with sm8550, and it will
>> have different memory reserved for the firmware to be used.
>> While firmware release along with memory map was not settled down yet.
>> That's why currently qcs8550.dtsi is an "empty file" and only include
>> sm8550.dtsi. As long as the firmware release is settled down, we will
>> have more detailed different node here.
> 
> So the DTS is not really usable now?
curent qcs8550.dtsi is an "empty file" which is identical to "sm8550.dtsi".
While qcs8550-aim300-itot.dts is currently used with a "temporary 
reserved memory" for those engineer qcs8550 firmware for boot up and 
limited function verify.

So the idea here is to postpone only the firmware related reserved 
memory part. And open an "empty file" qcs8550.dtsi for common which can 
be used for other board like qcs8550-rb5-gen2.
>>
>> By the way, RB5 gen2 will also relies on the current qcs8550.dtsi, since
>> it is using the same qcs8550 soc, and will use the same firmware release.
>>
>> We have patch version2 remove the qcs8550.dtsi, and have SOM dtsi
>> qcs8550-aim300.dtsi include the sm8550.dtsi. While after discussion, our
>> understanding is that we can have an qcs8550.dtsi like this. Feel free
>> to let us know if it is not right understanding.
>>
>>>
>>> It's really confusing now.
>>
>> We can have a syncup to clear the confusing point if needed. :)
>>>
> 
> The code and commit msg are confusing. I need to keep asking you to get
> any information.
> 
> Best regards,
> Krzysztof
> 

-- 
Thx and BRs,
Aiqun(Maria) Yu