TK1 CPU clock frequency error messages


Currently I am working on an embedded project using Nvidia’s jetson TK1 board. I have builded up the customized linux kernel and u-boot through Yocto project. The Linux kernel version is 4.7

During startup I am seeing some error messages related to the cpu clock frequency, Can you please let me know what you think about the following error messages:

[ 0.000000] Tegra clk 127: register failed with -17
[ 0.075752] /cpus/cpu@0 missing clock-frequency property, len:-301236472
[ 0.080664] /cpus/cpu@1 missing clock-frequency property, len:-301236472
[ 0.087453] /cpus/cpu@2 missing clock-frequency property, len:-301236472
[ 0.094185] /cpus/cpu@3 missing clock-frequency property, len:-301236472
[ 0.977039] +USB0_VBUS_SW: Failed to request enable GPIO108: -517

And I am interested to know in which file the cpu clock frequency is set.

I have looked into the files in the kernel source … /drivers/clk/tegra , but couldn’t able to locate the file responsible to set the clock frequency

From the message it possible need the clock information in the device tree like below.

           cpu@0 {
                 compatible = "arm,cortex-a15";
                 device_type = "cpu";
                 clock-frequency = <1600000000>;
                 reg = <0>;

After setting the clock frequency property in the device tree no more errors related to missing clock-frequency property is visible.

But still I am seeing the errors related to Tegar clk

[ 0.000000] Tegra clk 127: register failed with -17

I think this message is harmless, it’s possible the number of items of the clks array are less than the clk_num. Could you check the size of the clks and clk_num?

void __init tegra_add_of_provider(struct device_node *np)
int i;

for (i = 0; i < clk_num; i++) {
	if (IS_ERR(clks[i])) {
		    ("Tegra clk %d: register failed with %ld\n",
		     i, PTR_ERR(clks[i]));
	if (!clks[i])
		clks[i] = ERR_PTR(-EINVAL);