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

[Mark Rutland]

On Fri, Sep 09, 2016 at 06:55:30AM +0000, S.H. Xie wrote:
> > 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@xxxxxxxxx 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.

Ok. Could you please place a comment in the dts to that effect?

Thanks,
Mark.