Ubiquity AP Pro lost ethernet


I have encountered problem with my Ubiquity AP Pro device running OpenWRT. It suddenly lost ethernet connectivity - link LEDs are not lit on both ports and on AP and devices connected.
Access point is reachable via WiFi only and dmesg shows that switch device is not initialized on boot:
[ 0.718382] libphy: Fixed MDIO Bus: probed
[ 0.756663] libphy: ag71xx_mdio: probed
[ 1.386859] ag71xx ag71xx.0: connected to PHY at ag71xx-mdio.0:00 [uid=00000000, driver=Generic PHY]
[ 1.396708] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode: rgmii

On similar device there is log entry for a switch device:

[ 0.718313] libphy: Fixed MDIO Bus: probed
[ 0.735576] switch0: Atheros AR8327 rev. 4 switch registered on ag71xx-mdio.0
[ 1.408854] libphy: ag71xx_mdio: probed
[ 2.036693] ag71xx ag71xx.0: connected to PHY at ag71xx-mdio.0:00 [uid=004dd034, driver=Atheros AR8216/AR8236/AR8316]
[ 2.048058] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode: rgmii

Is it possible to get some debug output from kernel for switch device probing? Perhaps there are more troubleshooting capabilities I'm missing?

Thanks a lot!

try plugging and unplugging the ethernet cable, see if there's a reaction in dmesg.

Those messages are independent from an actual cable being plugged in. The MDIO bus does not talk to the clients itself, it's further up the chain. What does not bode well is this [uid=00000000, driver=Generic PHY] whereas it should indeed be something like the second device has: [uid=004dd034, driver=Atheros AR8216/AR8236/AR8316]. Although that's probably a consequence of the probe not finding anything and no switch being detected.

@jeka_boo Those devices share identical hardware? Same revision etc.? Are they running the exact same OpenWrt version as well?

Try bringing up bootloader TFTP recovery mode by booting with the reset button held down until the LED starts blinking white-blue-off. If the link light on your switch still doesn't come on, there probably is hardware failure.

Doing this (but not actually putting a new firmware) should not disturb your firmware or settings.

Flashing back to stock is the best way to test for hardware failure.

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