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 <wxt@xxxxxxxxxxxxxx>
---
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
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