[PATCH v5 3/7] ARM: dts: Exynos542x/5800: add CPU OPP properties

On 11.12.2015 13:38, Viresh Kumar wrote:

On 11-12-15, 13:18, Krzysztof Kozlowski wrote:

quoted

We had such configuration before (before df09df6f9ac3). I don't see any
benefit in what you described. Where is the "thing" to be fixed? It is
mixed up. The contiguous ordering is easier to read and more natural.

This is what you are doing today (keeping on one CPU per cluster to
simplify it):

		cpu0: cpu at 0 {
			device_type = "cpu";
			compatible = "arm,cortex-a15";
			reg = <0x0>;
			clock-frequency = <1800000000>;
			cci-control-port = <&cci_control1>;
		};

		cpu4: cpu at 100 {
			device_type = "cpu";
			compatible = "arm,cortex-a7";
			reg = <0x100>;
			clock-frequency = <1000000000>;
			cci-control-port = <&cci_control0>;
		};


Then you overwrite it with:

                &cpu0 {
                	device_type = "cpu";
                	compatible = "arm,cortex-a7";
                	reg = <0x100>;
                	clock-frequency = <1000000000>;
                	cci-control-port = <&cci_control0>;
                };
                
                &cpu4 {
                	device_type = "cpu";
                	compatible = "arm,cortex-a15";
                	reg = <0x0>;
                	clock-frequency = <1800000000>;
                	cci-control-port = <&cci_control1>;
                };


Don't you think this isn't the right way of solving problems?

The DT overwrite feature isn't there to do such kind of stuff, though
it doesn't stop you from doing that.

This is quite ugly, indeed, and it is getting uglier :)... but it does
not violate the idea of DT to describe the hardware. Both hardware
descriptions - the 5420 and overridden - are entirely correct... because
the CPU ordering comes from booting sequence (actually code in IROM
decides according to pulled up GPIO gpg2-1).

Either you should keep separate paths for both the SoCs,

I like that idea. That makes it much more readable. Thanks for feedback!
I will send a patch for that.

or can solve
it the way I suggested earlier.

This came up because in the current series you are doing this:

		cpu0: cpu at 0 {
			compatible = "arm,cortex-a15";
                        operating-points-v2 = <&cpu0_opp_table>;
		};

		cpu4: cpu at 100 {
			device_type = "cpu";
			compatible = "arm,cortex-a7";
                        operating-points-v2 = <&cpu1_opp_table>;
		};


Then you overwrite it with:

                &cpu0 {
                	compatible = "arm,cortex-a7";
                        operating-points-v2 = <&cpu1_opp_table>;
                };
                
                &cpu4 {
                	compatible = "arm,cortex-a15";
                        operating-points-v2 = <&cpu0_opp_table>;
                };

Yes, it is getting uglier with each change...

Best regards,
Krzysztof