CodeSys killing eth0 on Raspberry Pi 4?

Question

I'm running into a very strange issue attempting to run CodeSys on a 4GB RasPi-4. Long story short, the Pi works fine right up until I start running the CodeSys project. When I do, within 60sec, eth0 goes down and cannot be brought back up. Even rebooting the Pi has no effect. The only way I've found to recover eth0 is to re-burn RasPiOS from the source image from Raspberrypi.org (which I've done about 30 times over the past few days, trying to trial-and-error my way out of this).

Linux raspberrypi 5.4.79-v7l+ #1373 SMP Mon Nov 23 13:27:40 GMT 2020 armv7l GNU/Linux

I have eth0 set to a static IP using /etc/dhcpcd.conf. Whatever is causing this issue is not altering my settings there. Attempts to use ifconfig eth0 up/down have no effect -- no errors, no feedback, just nothing. Checking eth0's state shows "waiting for carrier," despite being connected to an active switch (I've also swapped out all the cables and the switch to eliminate them as the source of the problem).

When I re-burn the Pi and install CodeSys, eth0 stays up indefinitely (24hrs+ in my longest test). It's starting the CodeSys project that kills eth0. A reboot after etho "dies" gives a series of bcmgenet messages that appear to be related:

pi@raspberrypi:~ $ dmesg | grep bcmg
[    1.033665] bcmgenet fd580000.ethernet: failed to get enet clock
[    1.033685] bcmgenet fd580000.ethernet: GENET 5.0 EPHY: 0x0000
[    1.033709] bcmgenet fd580000.ethernet: failed to get enet-wol clock
[    1.033730] bcmgenet fd580000.ethernet: failed to get enet-eee clock
[    1.044648] libphy: bcmgenet MII bus: probed
[    9.528502] bcmgenet fd580000.ethernet: configuring instance for external RGMII
[    9.535175] bcmgenet fd580000.ethernet eth0: Link is Down

I also tried creating a new CodeSys project from scratch that had no eth0 drivers (ModBus, Ethernet/IP) installed, only the GPIO driver. That didn't help either -- eth0 dies within 60sec.

The strangest part is, only eth0 seems to be affected. The GPIO pins keep cycling as controlled by the CodeSys project (I have a simple LED-blinking program running), and I can still SSH into the Pi using wifi. But since my main reason for setting this Pi up is to use Ethernet/IP and ModBus....

This thread: at GitHub is the only place I've found anyone describing anything similar to what I'm experiencing, but in that case CodeSys is not installed. I did try adding genet.skip_umac_reset=n to my cmdline.txt as suggested in the thread, but it had no effect.

question from:https://stackoverflow.com/questions/65892442/codesys-killing-eth0-on-raspberry-pi-4

Answer 1

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