Re: [PATCH v2 1/3] arm64: dts: qcom: sc7280: Add memory region for audiopd

[Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>]

On 5/22/25 7:51 PM, Dmitry Baryshkov wrote:
> On Thu, May 22, 2025 at 08:27:40PM +0200, Konrad Dybcio wrote:
>> On 5/22/25 2:16 PM, Dmitry Baryshkov wrote:
>>> On Thu, 22 May 2025 at 13:44, Ling Xu <quic_lxu5@quicinc.com> wrote:
>>>>
>>>> 在 5/20/2025 9:53 PM, Dmitry Baryshkov 写道:
>>>>> On Tue, May 20, 2025 at 02:41:22PM +0800, Ling Xu wrote:
>>>>>> 在 5/17/2025 5:47 AM, Dmitry Baryshkov 写道:
>>>>>>> On Fri, May 16, 2025 at 04:30:27PM +0530, Ling Xu wrote:
>>>>>>>> Add reserved memory region and VMIDs for audio PD dynamic loading and
>>>>>>>> remote heap memory requirements.
>>>>>>>
>>>>>>> Why? Was it not working without this heap?
>>>>>>
>>>>>> yes, it will not working without this heap.
>>>>>> Memory region is required for audio PD for dynamic loading and remote heap memory
>>>>>> requirements. For more info, please refer below patches, it has provided a more
>>>>>> detailed explanation.
>>>>>> https://lore.kernel.org/all/bb68da04-ef52-4172-8b6e-f4027bcc2786@oss.qualcomm.com/
>>>>>> https://lore.kernel.org/all/effea02f-6ffb-42e9-87df-081caafab728@oss.qualcomm.com/
>>>>>
>>>>> This triggers a bunch of questions:
>>>>>
>>>>> - What is audio PD?
>>>>>
>>>> Audio PD is a protection domain which is running on DSP for audio
>>>> specific processing.
>>>>> - Is it a required component?
>>>> yes. it is needed wherever there is some audio use cases where
>>>> DSP audio PD dynamic loading is needed.
>>>
>>> Which use cases?
>>>

Usecase is for audio compress offload, ex: when we play mp3 or any other
compress format, we need audio pd support.



thanks,
Srini
>>>>> - For which platforms ?
>>>>>
>>>> For platforms that require dynamic loading of DSP audio PD.
>>>
>>> Please be more specific, we are not playing a guessing game here.
>>>
>>>>> - What happens if there is a memory region, but it is not used by the
>>>>>   driver (SM8650, SM8550).
>>>>>
>>>> It won't be used.
>>>
>>> So, what happens? DSP crash? system reboot? blue smoke coming from the SoC?
>>>
>>> I'm asking all those questions to understand:
>>> - whether this is applicable to previous SC7280 platforms or just RB3Gen2 / IDP
>>> - whether this needs to be backported or not
>>> - whether a similar fix should be applied to other platforms.
>>
>> I wouldn't worry about FP5 too much (albeit it's apparently not easy
>> to test it out and even having spent some time trying to, I couldn't
>> figure out how these things connect), but the chromebooks may be
>> potentially problematic. That said, we can overwrite it in sc7280-chrome
>> if necessary
> 
> What about NothingPhone?
>