...or any of Friendly's bundled images for Linux. This is I think due to the code missing in the Kernel. As you can see below, the PCIE bus basically doesn't exist in this kernel and the kernel doesn't know what to do with it.

root@NanoPC-T4:~# uname -a
Linux NanoPC-T4 4.4.179 #1 SMP Tue Sep 15 15:56:24 CST 2020 aarch64 aarch64 aarch64 GNU/Linux
root@NanoPC-T4:~# lspci
root@NanoPC-T4:~# dmesg | grep pcie
[ 0.634999] rockchip-pcie f8000000.pcie: GPIO lookup for consumer ep
[ 0.635028] rockchip-pcie f8000000.pcie: using device tree for GPIO lookup
[ 0.635059] of_get_named_gpiod_flags: parsed 'ep-gpios' property of node '/pcie@f8000000[0]' - status (0)
[ 0.635291] rockchip-pcie f8000000.pcie: no vpcie3v3 regulator found
[ 0.635861] rockchip-pcie f8000000.pcie: no vpcie1v8 regulator found
[ 0.636440] rockchip-pcie f8000000.pcie: no vpcie0v9 regulator found
[ 0.637003] rockchip-pcie f8000000.pcie: missing "memory-region" property
[ 0.637613] PCI host bridge /pcie@f8000000 ranges:
[ 1.160101] rockchip-pcie f8000000.pcie: PCIe link training gen1 timeout!
[ 1.160716] rockchip-pcie f8000000.pcie: deferred probe failed
[ 1.161482] rockchip-pcie: probe of f8000000.pcie failed with error -110

Apparently the fix is to take an approach like @redfish below. I haven't been able to get a 5.x.x kernel to work yet. Would love some help there.


Linking redfish's
viewtopic.php?f=61&t=3246