From mboxrd@z Thu Jan 1 00:00:00 1970 From: Caesar Wang Subject: Re: [PATCH v2 2/5] dt-bindings: gpu: add a power_model optional properties for MALI Date: Tue, 18 Jul 2017 08:58:50 +0800 Message-ID: <3b464bab-2d72-717c-3aa0-410b1e1bd930@rock-chips.com> References: <1500279271-15249-1-git-send-email-wxt@rock-chips.com> <1500279271-15249-3-git-send-email-wxt@rock-chips.com> <20170717200733.nax6jfbvs3rjd7t4@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20170717200733.nax6jfbvs3rjd7t4@rob-hp-laptop> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Heiko Stuebner , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, rocky.hao-TNX95d0MmH7DzftRWevZcw@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, David Airlie , Mark Rutland List-Id: devicetree@vger.kernel.org Rob, 在 2017年07月18日 04:07, Rob Herring 写道: > On Mon, Jul 17, 2017 at 04:14:28PM +0800, Caesar Wang wrote: >> This patch adds the MALI's power-model to set the IPA model to be used >> for power management. > What's IPA? India Pale Ale or Intermediate Physical Address? IPA is intelligent Power Allocator. (As the ARM introduced on https://developer.arm.com/open-source/intelligent-power-allocation) > >> Signed-off-by: Caesar Wang >> --- >> >> Changes in v2: None >> >> Documentation/devicetree/bindings/gpu/arm,mali-midgard.txt | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/gpu/arm,mali-midgard.txt b/Documentation/devicetree/bindings/gpu/arm,mali-midgard.txt >> index a461e47..b616e6b 100644 >> --- a/Documentation/devicetree/bindings/gpu/arm,mali-midgard.txt >> +++ b/Documentation/devicetree/bindings/gpu/arm,mali-midgard.txt >> @@ -37,6 +37,18 @@ Optional properties: >> - operating-points-v2 : Refer to Documentation/devicetree/bindings/power/opp.txt >> for details. >> >> +- power_model : Sets power model parameters. Note that this model was designed for the Juno >> + platform, and may not be suitable for other platforms. A structure containing : >> + - compatible: Should be arm,mali-simple-power-model >> + - dynamic-coefficient: Coefficient, in pW/(Hz V^2), which is multiplied >> + by v^2*f to calculate the dynamic power consumption. >> + - static-coefficient: Coefficient, in uW/V^3, which is multiplied by >> + v^3 to calculate the static power consumption. >> + - ts: An array containing coefficients for the temperature scaling >> + factor. This is used to scale the static power by a factor of >> + tsf/1000000, where tsf = ts[3]*T^3 + ts[2]*T^2 + ts[1]*T + ts[0], >> + and T = temperature in degrees. >> + - thermal-zone: A string identifying the thermal zone used for the GPU > This can all easily be implied by the compatible string. I'm not > inclined to accept something Mali specific here. Isn't arm,mali-midgard.txt document suit for Mali specific? :-) > > This looks *very* precise, but I'd be surprised if these values are any > more than magic values (at least the dynamic coef) adjusted until the > desired power/performance requirements are achieved. To put it another > way, why don't we have similar values for CPUs? These value was calculated by running full GPU process. CPU had the similar value for dtsi. Say: arch/arm64/boot/dts/rockchip/rk3399.dtsi cpu_b0: cpu@100 { ... dynamic-power-coefficient = <436>; ... }; -Caesar > > Rob > > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html