Add nsessions property for adsp context bank to make sessions
available for ADSP offload.

Co-developed-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
Signed-off-by: Ling Xu <quic_lxu5@quicinc.com>
---
 arch/arm64/boot/dts/qcom/sc7280.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
index b1def5611764..5a1eacb6685e 100644
--- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
@@ -3939,6 +3939,7 @@ compute-cb@5 {
 						compatible = "qcom,fastrpc-compute-cb";
 						reg = <5>;
 						iommus = <&apps_smmu 0x1805 0x0>;
+						qcom,nsessions = <5>;
 						dma-coherent;
 					};
 				};
-- 
2.34.1

On Tue, Jul 01, 2025 at 02:19:05PM +0530, Ling Xu wrote:
> Add nsessions property for adsp context bank to make sessions
> available for ADSP offload.

- Describe the problem, describe _how_ the commit solves it.

> 
> Co-developed-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
> Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
> Signed-off-by: Ling Xu <quic_lxu5@quicinc.com>
> ---
>  arch/arm64/boot/dts/qcom/sc7280.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> index b1def5611764..5a1eacb6685e 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> @@ -3939,6 +3939,7 @@ compute-cb@5 {
>  						compatible = "qcom,fastrpc-compute-cb";
>  						reg = <5>;
>  						iommus = <&apps_smmu 0x1805 0x0>;
> +						qcom,nsessions = <5>;
>  						dma-coherent;
>  					};
>  				};
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry

On 8/11/25 12:42 PM, Dmitry Baryshkov wrote:
> On Tue, Jul 01, 2025 at 02:19:05PM +0530, Ling Xu wrote:
>> Add nsessions property for adsp context bank to make sessions
>> available for ADSP offload.
> 
> - Describe the problem, describe _how_ the commit solves it.

This is pure software configuration, the only real limitation is that
the total amount of sessions per channel can't exceed 14 (because our
driver says so? I have conflicting information where this number comes
from), but no more than 5 is recommended for optimal performance

I'd rather waste a couple of bytes and pre-alloc the maximum amount on
every channel, so that if someone decides they want to use the DSPs ever
so slightly differently, they don't have to run around changing the DT..

Konrad