Re: [PATCH 3/4] arm64: dts: qcom: sdm630: describe adsp_mem region properly

[Nickolay Goppen]

I'm assigning this region in the fourth patch

17 апреля 2026 г. 18:15:45 GMT+03:00, Ekansh Gupta <ekansh.gupta@xxxxxxxxxxxxxxxx> wrote:
>On 15-04-2026 15:22, Konrad Dybcio wrote:
>> On 4/15/26 11:40 AM, Nickolay Goppen wrote:
>>> Downstream [1] this region is marked as shared and reusable so
>>> describe it that way.
>>>
>>> [1]: https://github.com/xiaomi-sdm660/android_kernel_xiaomi_sdm660/blob/11-EAS/arch/arm/boot/dts/qcom/sdm660.dtsi#L448
>>>
>>> Signed-off-by: Nickolay Goppen <setotau@xxxxxxxxxxxxxx>
>>> ---
>> 
>> +Ekansh some insight, please?
>> 
>> We're giving away that memory via qcom_scm_assign_mem() anyway
>> and I would assume that making it not-"no-map" could introduce issues
>> when the OS tries to access that region
>> 
>With the current version and the upcoming planned enhancements, I don't
>see any major benefits of making this as not-"no-map".
>
>With posted enhancements[1], the plan is to qcom_scm_assign_mem() the
>entire memory-region to lpass VMIDs. and un-assign it only during
>fastrpc_rpmsg_remove(). There have been implementation in downstream
>where this memory is dumped in case of SSR or audio PDR using minidump,
>so marking it `reusable` might make sense there, but that dump logic is
>not added upstream.
>
>Upon checking the DT, I see a bigger problem here, this memory-region
>looks to me unused, it's not added under fastrpc adsp node(ref. [2]).
>Please correct me if I am wrong about this point.
>
>[1]
>https://lore.kernel.org/all/20260409062617.1182-1-jianping.li@xxxxxxxxxxxxxxxx/
>[2]
>https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm64/boot/dts/qcom/lemans.dtsi#n7500
>
>//Ekansh
>> Konrad
>> 
>> 
>>>  arch/arm64/boot/dts/qcom/sdm630.dtsi | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/sdm630.dtsi b/arch/arm64/boot/dts/qcom/sdm630.dtsi
>>> index 4b47efdb57b2..13094b5e9339 100644
>>> --- a/arch/arm64/boot/dts/qcom/sdm630.dtsi
>>> +++ b/arch/arm64/boot/dts/qcom/sdm630.dtsi
>>> @@ -495,8 +495,9 @@ venus_region: venus@9f800000 {
>>>  		};
>>>  
>>>  		adsp_mem: adsp-region@f6000000 {
>>> +			compatible = "shared-dma-pool";
>>>  			reg = <0x0 0xf6000000 0x0 0x800000>;
>>> -			no-map;
>>> +			reusable;
>>>  		};
>>>  
>>>  		qseecom_mem: qseecom-region@f6800000 {
>>>

Best regards
Nickolay