[FS#330] xrx200-net: kenrel panic

[LEDE Bugs]

The following task has a new comment added:

FS#330 - xrx200-net: kenrel panic
User who did this - Michael Thomson (michthom)

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I've kept trying new builds in vain hope, but up to r3581-23dff07 there's no change.

Empirically, the point the LAN cable is attached in the boot process is important. Any of the LAN ports behave similarly (note I have mine set to request an address using DHCP, I don't know if that's relevant). Plugging the LAN cable into the WAN port with that on the default of pppoe doesn't provoke a reboot - at least in the few tries I gave that combination. Should I switch the LAN port to DHCP? I wasn't sure if that'd provide useful information or just be confounding.

If the LAN cable is attached before the HH5a powers up, there's a strong probability (but not certainty) that it'll encounter the kernel unaligned access. (P.S. I'm not sure if the packet trace I provided for Matthias was ever useful in provoking this behaviour synthetically?)

If I plug in during the boot sequence there's a definite tipping point - later in the process, but *before* the point it panics when plugged in from boot - then it seems to start up normally. My guess is the behaviour changes if the cable goes in after the following lines, but everything is going pretty fast so it's hard to be sure:
[    1.212639] eth0: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:00, irq=-1)
[    1.280615] eth0: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:01, irq=-1)
[    1.348600] eth0: attached PHY [Lantiq XWAY VR9 GPHY 11G v1.4] (phy_addr=0:11
, irq=-1)
[    1.416599] eth0: attached PHY [Lantiq XWAY VR9 GPHY 11G v1.4] (phy_addr=0:13
, irq=-1)
[    1.424675] net-xrx200: invalid MAC, using random
[    1.492620] eth1: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:05, irq=-1)


Does any of this help? Can I do anything to assist further? I'm aware you wanted a binary search of my network devices to find a culprit but I'm struggling against demanding family members who object to Dad unplugging The Internet from their gadgets at inconvenient moments ;-)
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https://bugs.lede-project.org/index.php?do=details&task_id=330#comment1968