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From:   Jerome Brunet <jbrunet@baylibre.com>
To:     elatllat@gmail.com
Cc:     mark.rutland@arm.com, devicetree@vger.kernel.org,
        joy.cho@hardkernel.com, narmstrong@baylibre.com,
        khilman@baylibre.com, christianshewitt@gmail.com,
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        tobetter@gmail.com, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4] arm64: dts: meson: S922X: extend cpu opp-points
In-reply-to: <20200426162119.GA23268@imac>
Date:   Mon, 27 Apr 2020 11:06:27 +0200
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On Sun 26 Apr 2020 at 18:21, Tim Lewis <elatllat@gmail.com> wrote:

> Add extra cpu pop points to allow mild overclock on S922X. The opp
> points are found in Hardkernel N2 sources [1] and testing shows no
> obvious issues on other S922X devices. Thermal throttling should
> keep things in-check if needed.

The Odroid-N2 has a massive heatsink mounted.
Do we have any idea if this applies (is safe) on any other S922x
device ?

It would be nice to get some input (review) from Amlogic is this to
included for any devices using the SoC.

In the meantime, I think this should be applied to odroid-n2 dt only.

>
> [1] https://github.com/hardkernel/linux/commit/f86cd9487c7483b2a05f448b9ebacf6bd5a2ad2f
> Tested-by: Christian Hewitt <christianshewitt@gmail.com>
> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
> Signed-off-by: Tim Lewis <elatllat@gmail.com>
>
> ---
>  arch/arm64/boot/dts/amlogic/meson-g12b-s922x.dtsi | 15 +++++++++++++++
>  1 files changed, 15 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-s922x.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12b-s922x.dtsi
> index 046cc332d..1e5d0ee5d 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-s922x.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-s922x.dtsi
> @@ -65,6 +65,11 @@
>  			opp-hz = /bits/ 64 <1896000000>;
>  			opp-microvolt = <981000>;
>  		};
> +
> +		opp-1992000000 {
> +			opp-hz = /bits/ 64 <1992000000>;
> +			opp-microvolt = <1001000>;
> +		};
>  	};
>  
>  	cpub_opp_table_1: opp-table-1 {
> @@ -120,5 +125,15 @@
>  			opp-hz = /bits/ 64 <1704000000>;
>  			opp-microvolt = <891000>;
>  		};
> +
> +		opp-1800000000 {
> +			opp-hz = /bits/ 64 <1800000000>;
> +			opp-microvolt = <981000>;
> +		};
> +
> +		opp-1908000000 {
> +			opp-hz = /bits/ 64 <1908000000>;
> +			opp-microvolt = <1022000>;
> +		};
>  	};
>  };