Re: [PATCH v2] arm64: dts: monaco: extend fastrpc compute cb

From: Srinivas Kandagatla

Date: Mon Mar 30 2026 - 04:44:39 EST


On 3/27/26 1:10 PM, Konrad Dybcio wrote:
> On 3/26/26 4:41 PM, Srinivas Kandagatla wrote:
>> For some reason we ended up adding only 4 out of 11 compute cb's for
>> CDSP, add the missing compute cb. This will also improve the end
>> user-experience by enabling running multiple AI usecases in parallel.
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
>> ---
>> arch/arm64/boot/dts/qcom/monaco.dtsi | 49 ++++++++++++++++++++++++++++
>> 1 file changed, 49 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/monaco.dtsi b/arch/arm64/boot/dts/qcom/monaco.dtsi
>> index 10e799dd4a78..38fbd44c7d8f 100644
>> --- a/arch/arm64/boot/dts/qcom/monaco.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/monaco.dtsi
>> @@ -7739,6 +7739,55 @@ compute-cb@4 {
>> <&apps_smmu 0x1964 0x0400>;
>> dma-coherent;
>> };
>> +
>> + compute-cb@5 {
>> + compatible = "qcom,fastrpc-compute-cb";
>> + reg = <5>;
>> + iommus = <&apps_smmu 0x19c5 0x0400>;
>
> I see that the other CBs have 2 iommu streams, the other one
> having "DMA" in the name - could you shed some light on that?

AFAIU, These DMA streams are relevant when NPU dma engine is in the
picture, examples can be data pipelines which involve transferring data
buffers(in/out) in-cordination with different IP blocks outside DSP. May
be something like camera/video streams directly to NPU without CPU
involving...

Personally I have not tested such usecases, but for upstream fastrpc
clients AFAIK only application streams matter as clients will explicitly
allocate the data buffers, even for sharing across ip-blocks.

--srini

>
> Konrad