[dxld]

I found networking/switchdev.txt very approachable. It documents all those different bridge+vlan (aware/unaware) configs you can do: https://docs.kernel.org/networking/switchdev.html

In particular I've learned from that doc that there's special handling for putting a vlan device on top of a bridge (br0.123) even if the bridge is vlan unaware.

DSA might also be relevant if you're working with hardware that supports it: https://docs.kernel.org/networking/dsa/dsa.html