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Date: Wed, 31 Jan 2024 06:08:31 +0100
From: Dragan Simic <dsimic@manjaro.org>
To: Alexey Charkov <alchark@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski
 <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>,
 Heiko Stuebner <heiko@sntech.de>, Daniel Lezcano
 <daniel.lezcano@linaro.org>, Viresh Kumar <viresh.kumar@linaro.org>,
 devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/4] arm64: dts: rockchip: Add further granularity in
 RK3588 CPU OPPs
In-Reply-To: <20240130-rk-dts-additions-v2-4-c6222c4c78df@gmail.com>
References: <20240130-rk-dts-additions-v2-0-c6222c4c78df@gmail.com>
 <20240130-rk-dts-additions-v2-4-c6222c4c78df@gmail.com>
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Hello Alexey,

On 2024-01-30 19:21, Alexey Charkov wrote:
> This introduces additional OPPs that share the same voltage as
> another OPP already present in the .dtsi but with lower frequency.
> 
> The idea is to try and limit system throughput more gradually upon
> reaching the throttling condition for workloads that are close to
> sustainable power already, thus avoiding needless performance loss.
> 
> My limited synthetic benchmarking [1] showed around 3.8% performance
> benefit when these are in place, other things equal (not meant to
> be comprehensive though).

I'm fine with this two-patch approach, so this important new feature
can be merged quicker, hopefully in the current merge window.  We can
add more OPPs later, after the additional testing is performed, of
course if all checks out as expected.

> [1] 
> https://lore.kernel.org/linux-rockchip/CABjd4YxqarUCbZ-a2XLe3TWJ-qjphGkyq=wDnctnEhdoSdPPpw@mail.gmail.com/T/#me92aa0ee25e6eeb1d1501ce85f5af4e58b3b13c5
> 
> Signed-off-by: Alexey Charkov <alchark@gmail.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3588s.dtsi | 87 
> +++++++++++++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> index af8b932a04c1..506676985a7e 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> @@ -360,6 +360,21 @@ cluster0_opp_table: opp-table-cluster0 {
>  		compatible = "operating-points-v2";
>  		opp-shared;
> 
> +		opp-408000000 {
> +			opp-hz = /bits/ 64 <408000000>;
> +			opp-microvolt = <675000 675000 950000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-600000000 {
> +			opp-hz = /bits/ 64 <600000000>;
> +			opp-microvolt = <675000 675000 950000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-816000000 {
> +			opp-hz = /bits/ 64 <816000000>;
> +			opp-microvolt = <675000 675000 950000>;
> +			clock-latency-ns = <40000>;
> +		};
>  		opp-1008000000 {
>  			opp-hz = /bits/ 64 <1008000000>;
>  			opp-microvolt = <675000 675000 950000>;
> @@ -392,6 +407,27 @@ cluster1_opp_table: opp-table-cluster1 {
>  		compatible = "operating-points-v2";
>  		opp-shared;
> 
> +		opp-408000000 {
> +			opp-hz = /bits/ 64 <408000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +			opp-suspend;
> +		};
> +		opp-600000000 {
> +			opp-hz = /bits/ 64 <600000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-816000000 {
> +			opp-hz = /bits/ 64 <816000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-1008000000 {
> +			opp-hz = /bits/ 64 <1008000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
>  		opp-1200000000 {
>  			opp-hz = /bits/ 64 <1200000000>;
>  			opp-microvolt = <675000 675000 1000000>;
> @@ -422,6 +458,21 @@ opp-2208000000 {
>  			opp-microvolt = <987500 987500 1000000>;
>  			clock-latency-ns = <40000>;
>  		};
> +		opp-2256000000 {
> +			opp-hz = /bits/ 64 <2256000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-2304000000 {
> +			opp-hz = /bits/ 64 <2304000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-2352000000 {
> +			opp-hz = /bits/ 64 <2352000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
>  		opp-2400000000 {
>  			opp-hz = /bits/ 64 <2400000000>;
>  			opp-microvolt = <1000000 1000000 1000000>;
> @@ -433,6 +484,27 @@ cluster2_opp_table: opp-table-cluster2 {
>  		compatible = "operating-points-v2";
>  		opp-shared;
> 
> +		opp-408000000 {
> +			opp-hz = /bits/ 64 <408000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +			opp-suspend;
> +		};
> +		opp-600000000 {
> +			opp-hz = /bits/ 64 <600000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-816000000 {
> +			opp-hz = /bits/ 64 <816000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-1008000000 {
> +			opp-hz = /bits/ 64 <1008000000>;
> +			opp-microvolt = <675000 675000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
>  		opp-1200000000 {
>  			opp-hz = /bits/ 64 <1200000000>;
>  			opp-microvolt = <675000 675000 1000000>;
> @@ -463,6 +535,21 @@ opp-2208000000 {
>  			opp-microvolt = <987500 987500 1000000>;
>  			clock-latency-ns = <40000>;
>  		};
> +		opp-2256000000 {
> +			opp-hz = /bits/ 64 <2256000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-2304000000 {
> +			opp-hz = /bits/ 64 <2304000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
> +		opp-2352000000 {
> +			opp-hz = /bits/ 64 <2352000000>;
> +			opp-microvolt = <1000000 1000000 1000000>;
> +			clock-latency-ns = <40000>;
> +		};
>  		opp-2400000000 {
>  			opp-hz = /bits/ 64 <2400000000>;
>  			opp-microvolt = <1000000 1000000 1000000>;