How do you overclock the VF2?

easytarget · June 2, 2023, 1:38pm

Looking further we have:

starfive-tech/linux/blob/JH7110_VisionFive2_upstream/arch/riscv/boot/dts/starfive/jh7110.dtsi#L195


      
          					opp-microvolt = <800000>;
          			};
          			opp-500000000 {
          					opp-hz = /bits/ 64 <500000000>;
          					opp-microvolt = <800000>;
          			};
          			opp-750000000 {
          					opp-hz = /bits/ 64 <750000000>;
          					opp-microvolt = <800000>;
          			};
          			opp-1500000000 {
          					opp-hz = /bits/ 64 <1500000000>;
          					opp-microvolt = <1040000>;
          			};
          	};
          
          
	dvp_clk: dvp-clock {
          		compatible = "fixed-clock";
          		clock-output-names = "dvp_clk";
          		#clock-cells = <0>;
          	};

I’d start by adding a new entry to that, below the 1500000 (1.5Ghz) definition.

			opp-1800000000 {
					opp-hz = /bits/ 64 <1800000000>;
					opp-microvolt = <1040000>;
			};

The big issue is the opp-microvolt value, if you look at the frequency list you will see it stays at 800000 up to 750Mhz (0.8 volts, presumably), but goes up to 1040000 (1.04 volts) for the 1.5Ghz band.

I’d start by trying the same opp-microvolt setting for 1.8GHz as used for 1.5. But it /may/ need increasing… a lack of system stability will quickly tell you if it is an issue. I have no idea of this values stepping and/or limits for the JH7110 so digging into the datasheet and other sources is necessary! Don’t just casually mess with this value without understanding it first, if the cpu max is 1v then increasing it further could be disastrous.