TX2 fails after flashing modified dtb to enable SPI

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

I have done everything on the forums, decompiled the device tree, added this:

spi@3240000{
compatible = “nvidia,tegra186-spi”;
reg = <0x0 0x3240000 0x0 0x10000>;
…
…
…
phandle = <0x184>;
spi@0 {
compatible = “spidev”;
reg = <0x0>;
spi-max-frequency = <0x1312D00>;
nvidia,enable-hw-based-cs;
nvidia,cs-setup-clk-count = <0x1e>;
nvidia,cs-hold-clk-count = <0x1e>;
nvidia,rx-clk-tap-delay = <0x1f>;
nvidia,tx-clk-tap-delay = <0x0>;
};
};

and then recompiled the tree

Then i took this new dtb file over to the SDK manager directory and replaced the one in nvidia/nvidia_sdk/JetPack_4.2_Linux_P3310/Linux_for_tegra/kernel/dtb

then i ran the flash.sh which run successfully
sudo ./flash.sh -r -k kernel-dtb jetson-tx2i mmcblk0p1

but then the Jetson doesnt boot up it throws errors at boot:

tegra-xusb 3530000.xhci: cannot find firmware…retry after 1 second
tegra-xusb 3530000.xhci: Direct firmware load for tegra18x_xusb_firmware failed with error -2
tegra-xusb 3530000.xhci: Falling back to user helper

and it keeps doing this every 60 seconds

What is my next step?

2

Looks like the problem was fixed?

3

Hi Shane

Yes I was able to get the spider.3.0 to show up but now when I test it, it reads zero all the time.

I’m making a basic external circuit using python, an LDR and a MCP3008 chip which I know works on the raspberry pi

The library I’m using was obtained by pip3 install spidev

Is there another library I should be using? I would like an example in python please this is an urgent task for me

Th aks!

4

Sorry, I don’t have experience for the python lib for SPI.
You can download the kernel source to build the spidev_test to verify.