Re: [PATCH v3 4/6] arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi

[Krzysztof Kozlowski]

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@xxxxxxxxxxx>
>>> ---
>>>   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.

> 
> 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?

> 
> 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