A20 OLinuXino Lime2 Rev L (armv7): Ethernet links at 1Gbps but transmits nothing — KSZ9031 PHY binds to Generic PHY driver

Board: Olimex A20-OLinuXino-LIME2, revision L (2018 silkscreen)
Image: Armbian 26.11 rolling, Trixie minimal, kernel 6.18.60-current-sunxi
Hardware: 1GB RAM, wired only

Summary: Ethernet negotiates 1000 Mbps full duplex, but no frame the board transmits ever arrives. Receive works — RX counters climb into the hundreds of thousands on broadcast traffic — while TX packets increment with TX errors static at 6 and nothing lands. DHCP never completes, ARP for the gateway never resolves (the only neighbour entry comes from the router's gratuitous ARP), and both ICMP and TCP fail.

Evidence:

sun7i-dwmac 1c50000.ethernet end0: PHY [stmmac-0:01] driver [Generic PHY] (irq=POLL)
sun7i-dwmac 1c50000.ethernet end0: configuring for phy/rgmii-id link mode

phy_id is **0x00221622** — a Microchip/Micrel KSZ9031. The mainline micrel driver supports this part, but it is not binding; the generic driver is used instead, so the RGMII-ID transmit delay and skew are never programmed. With rgmii-id the delays are meant to come from the PHY, and the generic driver applies none.

**Ruled out:**

- Two different cables and both LAN ports, all negotiating 1000 Mbps
- Router rebooted; DHCP confirmed enabled, 252-address pool, no MAC filtering, no isolation
- Both the Armbian-generated MAC and the board's hardware MAC — identical result
- Manual static address and default route: ping gives Destination Host Unreachable, curl to the router gets no response
- ip -s link show end0: TX errors remain at 6 across repeated tests, so the driver believes transmit succeeds
- Same board, cable and port work correctly on the Olimex Debian bookworm 5.10 image, where the PHY binds a specific driver

**Question:** Is there a Rev L device tree that declares the correct PHY compatible (ethernet-phy-id0022.1622), or an overlay to force the micrel driver and its skew defaults? The board has no usable networking on current Armbian until transmit works.