Re: [PATCH 02/20] arm64: dts: qcom: Introduce Kaanapali SoC

Jingyi Wang
2025-11-05T07:30:30Z

On 11/4/2025 8:54 PM, Konrad Dybcio wrote:
> On 11/4/25 10:04 AM, Jingyi Wang wrote:
>>
>>
>> On 10/14/2025 7:46 PM, Akhil P Oommen wrote:
>>>
>>>
>>> On 9/25/2025 5:47 AM, Jingyi Wang wrote:
>>>> Kaanapali is Snapdragon SoC from Qualcomm.
>>>>
>> <...>
>>>> +
>>>> +    reserved-memory {
>>>> +        #address-cells = <2>;
>>>> +        #size-cells = <2>;
>>>> +        ranges;
>>>> +
>>>
>>> This is missing a bunch of reserved regions which causes device crash when you stress memory allocation.
>>>
>>> -Akhil.
>>>
>>
>> Hi Akhil,
>>
>> We will not add all the reserved-memory in dts, other regions are designed to
>> be added in bootloader.
>
> If what Akhil says is true and Linux is crashing, something must be
> wrong..
>
> Konrad

Hi Konrad,

There was discussion about the reserved memory in QCS8550 change.
And the conclusion is that reserved memory regions which aren't relevant to
the kernel(like the hypervisor region) don't need to be described in DT to avoid
memory map change and update frequently. These regions will be runtime added
through bootloader.

ref:https://lore.kernel.org/all/20240618072202.2516025-3-quic_tengfan@quicinc.com/

The bootloader we currently use for Kaanapali has not supported this, and we have
solutions like add temp change to add these in DTS until the final bootloader is
provided.

Thanks,
Jingyi