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
>;
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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