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

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 3/30/26 10:38 AM, Srinivas Kandagatla wrote:
> 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@oss.qualcomm.com>
>>> ---
>>>  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.

This would be nice to confirm somewhere, perhaps even denote in bindings

+Ekansh could you confirm/speak more about this?
+Dmitry for awareness

Konrad