[PATCH net-next v3 00/12] net: airoha: Support multiple net_devices connected to the same GDM port

Lorenzo Bianconi
2026-04-06T10:35:01Z

EN7581 or AN7583 SoCs support connecting multiple external SerDes (e.g.
Ethernet or USB SerDes) to GDM3 or GDM4 ports via a hw arbiter that
manages the traffic in a TDM manner. As a result multiple net_devices can
connect to the same GDM{3,4} port and there is a theoretical "1:n"
relation between GDM ports and net_devices.

┌─────────────────────────────────┐
│ │ ┌──────┐
│ P1 GDM1 ├────►MT7530│
│ │ └──────┘
│ │ ETH0 (DSA conduit)
│ │
│ PSE/FE │
│ │
│ │
│ │ ┌─────┐
│ P0 CDM1 ├────►QDMA0│
│ P4 P9 GDM4 │ └─────┘
└──┬─────────────────────────┬────┘
│ │
┌──▼──┐ ┌────▼────┐
│ PPE │ │ ARB │
└─────┘ └─┬─────┬─┘
│ │
┌──▼──┐┌─▼───┐
│ ETH ││ USB │
└─────┘└─────┘
ETH1 ETH2

This series introduces support for multiple net_devices connected to the
same Frame Engine (FE) GDM port (GDM3 or GDM4) via an external hw
arbiter. Please note GDM1 or GDM2 does not support the connection with
the external arbiter.

---
Changes in v3:
- Fix MTU and VIP configuration when the GDM port is shared between
multiple net_devices.
- Add sanity check for nbq parameter.
- Add missing of_node_get() for net_device np node.
- Check if GDM port is shared before decresing device MTU.
- Move port forward configuration in airoha_dev_stop() before
configuring DMA tx/rx engine.
- Introduce PRIV_FLAG_WAN parameter.
- Link to v2: https://lore.kernel.org/r/20260401-airoha-eth-multi-serdes-v2-0-ac427ae4beeb@kernel.org

Changes in v2:
- Rename multiplexer in arbiter in the commit logs.
- Rebase on top of net-next main branch.
- Add missing PPE cpu port configuration for GDM2 when loopback is
enabled.
- Link to v1: https://lore.kernel.org/r/20260329-airoha-eth-multi-serdes-v1-0-00f52dc360ca@kernel.org

---
Lorenzo Bianconi (12):
dt-bindings: net: airoha: Add EN7581 ethernet-ports properties
net: airoha: Set PPE cpu port for GDM2 if loopback is enabled
net: airoha: Rely on net_device pointer in airoha_dev_setup_tc_block signature
net: airoha: Rely on net_device pointer in HTB callbacks
net: airoha: Rely on net_device pointer in ETS callbacks
net: airoha: Introduce airoha_gdm_dev struct
net: airoha: Move airoha_qdma pointer in airoha_gdm_dev struct
net: airoha: Rely on airoha_gdm_dev pointer in airhoa_is_lan_gdm_port()
net: airoha: Support multiple net_devices for a single FE GDM port
net: airoha: Do not stop GDM port if it is shared
net: airoha: Introduce WAN device flag
net: airoha: Rename get_src_port_id callback in get_sport

.../devicetree/bindings/net/airoha,en7581-eth.yaml | 44 +-
drivers/net/ethernet/airoha/airoha_eth.c | 725 ++++++++++++++-------
drivers/net/ethernet/airoha/airoha_eth.h | 39 +-
drivers/net/ethernet/airoha/airoha_ppe.c | 45 +-
4 files changed, 585 insertions(+), 268 deletions(-)
---
base-commit: 3741f8fa004bf598cd5032b0ff240984332d6f05
change-id: 20260324-airoha-eth-multi-serdes-fb4b556ee756

Best regards,
--
Lorenzo Bianconi <lorenzo@kernel.org>