How is RTL8372 support on OpenWrt?

Emre_Y · May 22, 2026, 6:49am

But is it built into upstream openwrt right now? Do I need to fetch this and build myself?

shi05275 · May 22, 2026, 6:52am

Yes, this driver hasn’t been integrated into the upstream OpenWrt repository yet. You’ll need to clone it and build it yourself.

ElektromAn · May 22, 2026, 8:17am

And will never be.

No DSA driver

Emre_Y · May 22, 2026, 9:31am

What?! no DSA? Just swconfig?? Nooooou
But surely if they have written swconfig very neatly, we could port to DSA?

ElektromAn · May 22, 2026, 10:04am

Read for yourself

github.com/torvalds/linux

Documentation/networking/dsa/dsa.rst

master

============
Architecture
============

This document describes the **Distributed Switch Architecture (DSA)** subsystem
design principles, limitations, interactions with other subsystems, and how to
develop drivers for this subsystem as well as a TODO for developers interested
in joining the effort.

Design principles
=================

The Distributed Switch Architecture subsystem was primarily designed to
support Marvell Ethernet switches (MV88E6xxx, a.k.a. Link Street product
line) using Linux, but has since evolved to support other vendors as well.

The original philosophy behind this design was to be able to use unmodified
Linux tools such as bridge, iproute2, ifconfig to work transparently whether
they configured/queried a switch port network device or a regular network
device.

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In a nutshell
with DSA you have real network interfaces.
with all dirty tricks the device will support.

AFAIR
There is some device in upstream/OpenWRT which has four or more switch ports, but will appear as real (independed) ethernet devices

dekarl · May 22, 2026, 10:44am

all of them that's the idea behind DSA.

Which means, supported switches have 50 or more Linux ethernet interfaces

ElektromAn · May 22, 2026, 12:03pm

and you can combine them as you wish

two or more switches, depends only on hw

Emre_Y · May 22, 2026, 7:29pm

Don't worry bros I am gonna do this But I need to have a free time and some coffee first.

shi05275 · May 23, 2026, 10:02am

I rewrote a version with the help of AI — it now supports DSA, so you can test it out. JiaY-shi/rtl837x-dsa-driver

ElektromAn · May 23, 2026, 3:16pm

The Makefile looks weird

From a quick look a some source files this also looks weird.
I can only assume this is DSA on top of swconfig

wfgriffin88 · July 18, 2026, 6:18am

In effort to add support for GL-MT5000 device, some new code has been released based in the source dump from GL.iNET & Realtek for RT8366ub + RT8371c switches (presumably from Realtek SDK).

Perhaps there is something useful in RT8371c source code. Check out the relevant discussions here:

wfgriffin88 · July 18, 2026, 6:40am

Here is another RTL8372n switch implementation by @perceival

github.com/perceival/openwrt-flint3

target/linux/qualcommbe/files-6.12/drivers/net/dsa/rtl8372n.c

main

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Realtek RTL8372N / RTL8373 DSA driver — minimal first cut
 *
 * Drives a Realtek RTL8372N-family switch attached on a Clause-22 MDIO bus.
 * The switch occupies a single PHY address on the bus and exposes its
 * internal 16-bit register space through four host MDIO registers (21..24)
 * — the protocol details are documented in
 * docs/rtl8372n-register-map.md in this work tree.
 *
 * This first cut covers only probe + chip-ID readback so we can confirm
 * the DT binding and MDIO transport. DSA port + VLAN logic comes in
 * follow-up patches.
 *
 * Copyright (c) 2026 Kamil Bienkiewicz <perceivalpercy@gmail.com>
 */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/debugfs.h>

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======

For comment on this Switch driver implementation, you can check out this discussion:

Emre_Y · July 23, 2026, 1:55pm

Oh my god, which I am gonna use then?? I am confused

longnt2007 · July 23, 2026, 2:15pm

For MT7988, I've tried the JiaY-shi rtl837x DSA driver and it works well, even though it's just a DSA wrapper over the Realtek RTK SDK, it saves you from having to deal with things like properly powering on the RTL8224 PHY on each port or implementing phylink_fixed_state for autoneg from scratch.

One caveat worth knowing: hardware NAT offload won't work regardless of which DSA driver you use. The root cause is architectural — MTK PPE can only offload flows through switches that use the MTK-compatible CPU tag format. The Realtek RTL8_4 tag (EtherType 0x8899) is not in that set, and there is no evidence the MT7988 PPE silicon can generate that tag format at egress. Software flow offload still works fine though.

Emre_Y · July 25, 2026, 8:04am

Hmm are you sure? It can be made that way afaik. It wouldn't be very difficult.

wfgriffin88 · July 29, 2026, 7:34am

More development in GL.iNET GL-BE9300 thread:

switching the RTL837x CPU tagging to the kernel’s tag_8021q DSA tagging path by @KakatkarAkshay
A refactored DSA RTL8372 driver by @airjinkela , who is also the author of RTL837x gsw driver earlier in this thread.

See direct GitHub project page here: https://github.com/RuijieNetworksCommunity/rtl837x-dsa-driver
Also, it appears that RTL8372N datasheet can now be found among Google search results

wfgriffin88 · August 6, 2026, 1:03pm

Seems there's some recent new code & development in this RTLPlayground project.