| Message ID | 1500974575-2244-1-git-send-email-wxt@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Dienstag, 25. Juli 2017, 17:22:55 CEST schrieb Caesar Wang: > This patch updates the dynamic-power-coefficient for big cluster on > rk3399 SoCs. > > The dynamic power consumption of the CPU is proportional to the square of > the Voltage (V) and the clock frequency (f). The coefficient is used to > calculate the dynamic power as below - > Pdyn = dynamic-power-coefficient * V^2 * f > Where Voltage is in uV, frequency is in MHz. > > As the following is the tested data on rk3399's big cluster. > frequency(MHz) Voltage(V) Current(mA) Dynamic-power-coefficient > 24 0.8 15 > 48 0.8 23 ~417 > 96 0.8 40 ~443 > 216 0.8 82 ~438 > 312 0.8 115 ~430 > 408 0.8 150 ~455 > So the dynamic-power-coefficient average value is about 436. > > Signed-off-by: Caesar Wang <wxt@rock-chips.com> applied for 4.14 and thanks for that very nice and informative commit message explaining the testing methodology. Heiko > --- > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > index 9d02006..5d54a06 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > @@ -150,7 +150,7 @@ > enable-method = "psci"; > #cooling-cells = <2>; /* min followed by max */ > clocks = <&cru ARMCLKB>; > - dynamic-power-coefficient = <100>; > + dynamic-power-coefficient = <436>; > }; > > cpu_b1: cpu@101 { > @@ -159,7 +159,7 @@ > reg = <0x0 0x101>; > enable-method = "psci"; > clocks = <&cru ARMCLKB>; > - dynamic-power-coefficient = <100>; > + dynamic-power-coefficient = <436>; > }; > }; > >
diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index 9d02006..5d54a06 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi @@ -150,7 +150,7 @@ enable-method = "psci"; #cooling-cells = <2>; /* min followed by max */ clocks = <&cru ARMCLKB>; - dynamic-power-coefficient = <100>; + dynamic-power-coefficient = <436>; }; cpu_b1: cpu@101 { @@ -159,7 +159,7 @@ reg = <0x0 0x101>; enable-method = "psci"; clocks = <&cru ARMCLKB>; - dynamic-power-coefficient = <100>; + dynamic-power-coefficient = <436>; }; };
This patch updates the dynamic-power-coefficient for big cluster on rk3399 SoCs. The dynamic power consumption of the CPU is proportional to the square of the Voltage (V) and the clock frequency (f). The coefficient is used to calculate the dynamic power as below - Pdyn = dynamic-power-coefficient * V^2 * f Where Voltage is in uV, frequency is in MHz. As the following is the tested data on rk3399's big cluster. frequency(MHz) Voltage(V) Current(mA) Dynamic-power-coefficient 24 0.8 15 48 0.8 23 ~417 96 0.8 40 ~443 216 0.8 82 ~438 312 0.8 115 ~430 408 0.8 150 ~455 So the dynamic-power-coefficient average value is about 436. Signed-off-by: Caesar Wang <wxt@rock-chips.com> --- arch/arm64/boot/dts/rockchip/rk3399.dtsi | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)