RE: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support

From	"S.H. Xie" <shaohui.xie@nxp.com>
Newsgroups	linux.kernel
Subject	RE: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support
Date	2016-09-09 11:30 +0200
Message-ID	<sfq8x-Za-7@gated-at.bofh.it> (permalink)
References	<seXpT-8mj-3@gated-at.bofh.it> <sf7fA-6dR-13@gated-at.bofh.it> <sf7pg-6h3-31@gated-at.bofh.it> <sf7pg-6h3-29@gated-at.bofh.it>
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> On Thu, Sep 08, 2016 at 02:13:26PM +0100, Mark Rutland wrote:
> > On Mon, Sep 05, 2016 at 06:01:31PM +0800, shh.xie@gmail.com wrote:
> > > +	cpus {
> > > +		#address-cells = <1>;
> > > +		#size-cells = <0>;
> > > +
> > > +		cpu0: cpu@0 {
> > > +			device_type = "cpu";
> > > +			compatible = "arm,cortex-a72";
> > > +			reg = <0x0>;
> > > +			clocks = <&clockgen 1 0>;
> > > +			next-level-cache = <&l2>;
> > > +			cpu-idle-states = <&CPU_PH20>;
> > > +		};
> >
> > [...]
> >
> > > +	};
> > > +
> > > +	idle-states {
> > > +		entry-method = "arm,psci";
> > > +
> > > +		CPU_PH20: cpu-ph20 {
> > > +			compatible = "arm,idle-state";
> > > +			idle-state-name = "PH20";
> > > +			arm,psci-suspend-param = <0x00010000>;
> > > +			entry-latency-us = <1000>;
> > > +			exit-latency-us = <1000>;
> > > +			min-residency-us = <3000>;
> > > +		};
> > > +	};
> >
> > There's no PSCI node in this file, and none from am included file, so
> > this doesn't look right.
> 
> Looking again, none of the cpu nodes has an enable-method property, and
> subsequent patches don't seem to add that to any cpu node.
> 
> Has this DT actually been tested?
[S.H] The PSCI node and the enable-method property are added by U-boot. 
U-boot can determine if using PSCI. If U-boot enables PSCI, it will add these 
missed parts in the dts. If not, it will not add these missed parts, 
so kernel will not use PSCI.

In other words, the dts does not enable PSCI by default. 
It's U-boot which adds the missed part if it determines to use PSCI.

Thanks,
Shaohui

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Re: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support Mark Rutland <mark.rutland@arm.com> - 2016-09-08 15:20 +0200
  Re: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support Mark Rutland <mark.rutland@arm.com> - 2016-09-09 11:20 +0200
    RE: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support "S.H. Xie" <shaohui.xie@nxp.com> - 2016-09-09 14:00 +0200
  RE: [PATCH 3/7] [v2] arm64: dts: add QorIQ LS1046A SoC support "S.H. Xie" <shaohui.xie@nxp.com> - 2016-09-09 11:30 +0200

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