i.MX6ULL 800Mhz running on 900Mhz

[Blackrose]

Hi, I got an imx6ull chip with model id is MCMX6Y2GVM08AA.And I had patched those patch file in my uboot and linux kernel source.The boot info of uboot shows max frequency is 792Mhz.After boot up the linux, I checked the file "

/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq" get value is 900000.Also I checked the clk_summary of debugfs, the pll1 is 792000000.When I running a memtest program, the pll1 will grow up to 900000000.

The model of chip is 800Mhz.Why the linux shows it can running 900Mhz?Is it overclock?

Below is imx6ull.dtsi from my kernel 4.1.43 version.

  cpus {
          #address-cells = <1>;
          #size-cells = <0>;

          cpu0: cpu@0 {
               compatible = "arm,cortex-a7";
               device_type = "cpu";
               reg = <0>;
               clock-latency = <61036>; /* two CLK32 periods */
               operating-points = <
                    /* kHz     uV */
                    996000     1275000
                    900000  1275000
                    792000     1225000
                    528000     1175000
                    396000     1025000
                    198000     950000
               >;
               fsl,soc-operating-points = <
                    /* KHz     uV */
                    996000     1175000
                    900000  1175000
                    792000     1175000
                    528000     1175000
                    396000     1175000
                    198000     1175000
               >;
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[b36401]

I suppose it should be some issue with Linux configuration. I mean it detects wrong cpuinfo_max_freq value for some reason.
As a workaround you can add toi startup a script that updates cpuinfo_max_freq value with "echo 792000 > /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq" command.

Have a great day,
Victor

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