I.MX8MQ: How can we increase the VPU G2 frequency?

[leslie_yu]

Hi,

How can we configure VPU G2 frequency as 660MHz?

Leslie

[leslie_yu]

Hi Yuri,

We modified assigned-clock-rates to 660000000 as the following in red but it does not work. We are also sure the voltage is 1.0v. Do you know what else we might miss?

vpu: vpu@38300000 {   compatible = "nxp,imx8mq-hantro";   reg = <0x0 0x38300000 0x0 0x200000>;   reg-names = "regs_hantro";   interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>, <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;   interrupt-names = "irq_hantro_g1", "irq_hantro_g2";   clocks = <&clk IMX8MQ_CLK_VPU_G1_ROOT>, <&clk IMX8MQ_CLK_VPU_G2_ROOT>, <&clk IMX8MQ_CLK_VPU_DEC_ROOT>;   clock-names = "clk_hantro_g1", "clk_hantro_g2", "clk_hantro_bus";   assigned-clocks = <&clk IMX8MQ_CLK_VPU_G1_SRC>, <&clk IMX8MQ_CLK_VPU_G2_SRC>, <&clk IMX8MQ_CLK_VPU_BUS_SRC>;   assigned-clock-parents = <&clk IMX8MQ_VPU_PLL_OUT>, <&clk IMX8MQ_VPU_PLL_OUT>, <&clk IMX8MQ_SYS1_PLL_800M>;   assigned-clock-rates = <600000000>, <660000000>, <800000000>;   power-domains = <&vpu_pd>;   regulator-supply = <&sw1c_reg>;   status = "disabled";  };

[Yuri]

Hello,

  please try 

assigned-clock-rates = <660000000>, <660000000>, <800000000>;  

Regards,

Yuri.

[leslie_yu]

We tried accordingly but it still does not work.

fsl-imx8mq.dtsi

        vpu: vpu@38300000 {

                compatible = "nxp,imx8mq-hantro";

                reg = <0x0 0x38300000 0x0 0x200000>;

                reg-names = "regs_hantro";

                interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>, <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;

                interrupt-names = "irq_hantro_g1", "irq_hantro_g2";

                clocks = <&clk IMX8MQ_CLK_VPU_G1_ROOT>, <&clk IMX8MQ_CLK_VPU_G2_ROOT>, <&clk IMX8MQ_CLK_VPU_DEC_ROOT>;

                clock-names = "clk_hantro_g1", "clk_hantro_g2", "clk_hantro_bus";

                assigned-clocks = <&clk IMX8MQ_CLK_VPU_G1_SRC>, <&clk IMX8MQ_CLK_VPU_G2_SRC>, <&clk IMX8MQ_CLK_VPU_BUS_SRC>;

                assigned-clock-parents = <&clk IMX8MQ_VPU_PLL_OUT>, <&clk IMX8MQ_VPU_PLL_OUT>, <&clk IMX8MQ_SYS1_PLL_800M>;

                assigned-clock-rates = <660000000>, <660000000>, <800000000>;

                power-domains = <&vpu_pd>;

                regulator-supply = <&sw1c_reg>;

                status = "disabled";

        };

cat /sys/kernel/debug/clk/clk_summary | grep -i vpu : 

    vpu_pll_ref_sel                       0            0    25000000          0 0

       vpu_pll_ref_div                    0            0     5000000          0 0

          vpu_pll                         0            0   600000000          0 0

             vpu_pll_bypass               0            0   600000000          0 0

                vpu_pll_out               0            0   600000000          0 0

                   vpu_g2_src             0            0   600000000          0 0

                      vpu_g2_cg           0            0   600000000          0 0

                         vpu_g2_pre_div           0            0   600000000          0 0

                            vpu_g2_div           0            0   600000000          0 0

                               vpu_g2_root_clk           0            0   600000000          0 0

                   vpu_g1_src             0            0   600000000          0 0

                      vpu_g1_cg           0            0   600000000          0 0

                         vpu_g1_pre_div           0            0   600000000          0 0

                            vpu_g1_div           0            0   600000000          0 0

                               vpu_g1_root_clk           0            0   600000000          0 0

[Yuri]

Hello,

   Do You use the recent NXP Linux BSP?

Regards,

Yuri.

[cphealy1]

I looked at the latest NXP BSP kernel's devicetree (5.4.3_2.0.0) and see that both the Hantro G1 and G2 are clocked at 600MHz.  Is there a reason that the latest NXP BSP devicetree does not have the Hantro G2 clocked at 660MHz?  According to the datasheet, the Hantro G1 should be at 600MHz and the Hantro G2 should be at 660MHz.

As an experiment, I tried running the Hantro G1 at 600, 660, 720, and 800MHz.  All of them seem to work fine with no stability issues and don't seem to result in any increase in core temperature.  This makes me wonder why the current frequencies of 600MHz and 660MHz were selected.  (All of my testing was done on a sample of 2 units so it could be that with some units the stability is an issue at increased frequencies.)

[Yuri]

Hello,

   Customers can try changing the Device Tree configuration on own risk.

fsl-imx8mq.dtsi\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel 

Have a great day,

Yuri

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