Jetson Nano SPI Bus Not Working

Because you haven’t shared the flash log, I don’t know which device tree are using (a00 or b00).
Maybe you could just apply the patch to tegra210-porg-gpio-p3448-0000-a00.dtsi and share the result of sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi again. The current result of that command seems not expected.

Is there no other way to determine which device tree I am using?

In any case, I modified the 00a file and attempted to build the kernel by running:

sudo ./ -o $PWD/kernel_out

as per the instructions. Then after a while I get:

Error: Missing kernel image /home/sr/Linux_for_Tegra/source/public/kernel_out/arch/arm64/boot/Image

And the kernel_out folder remains empty. Any ideas?

From your dmesg, it seems you are using tegra210-p3448-0000-p3449-0000-b00.dts.

Apr 18 09:05:28 sr-desktop kernel: [    0.420564] DTS File Name: /dvs/git/dirty/git-master_linux/kernel/kernel-4.9/arch/arm64/boot/dts/../../../../../../hardware/nvidia/platform/t210/porg/kernel-dts/tegra210-p3448-0000-p3449-0000-b00.dts

Re-build kernel should not be the issue about this topic.

Hi @KevinFFF ,
Can you guide me in more detail for step 2?
Thank you so much!