[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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Sorry Felix
I built r3293-f791fb4 with your patch, but I'm still getting unaligned access panics consistently.
There's no change in behaviour, though a slightly different call trace, see attached.

I can give you more Wireshark traces if it'd help, but I suspect there's no difference to those above.

I'll start weeding my LAN to see if I can figure out if this behaviour is due to a local bad actor...

[    2.210699] init: Console is alive
[    2.213019] init: - watchdog -
[    2.382312] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[    2.425788] dwc2 1e101000.ifxhcd: requested GPIO 495
[    3.284207] dwc2 1e101000.ifxhcd: DWC OTG Controller
[    3.287766] dwc2 1e101000.ifxhcd: new USB bus registered, assigned bus number 1
[    3.295136] dwc2 1e101000.ifxhcd: irq 62, io mem 0x00000000
[    3.300646] dwc2 1e101000.ifxhcd: Hardware does not support descriptor DMA mode -
[    3.308088] dwc2 1e101000.ifxhcd: falling back to buffer DMA mode.
[    3.315840] hub 1-0:1.0: USB hub found
[    3.318319] hub 1-0:1.0: 1 port detected
[    3.323848] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[    3.342213] init: - preinit -
[    3.540171] Unhandled kernel unaligned access[#1]:
[    3.543599] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.46 #0
[    3.549499] task: 805358f8 ti: 80526000 task.ti: 80526000
[    3.554884] $ 0   : 00000000 80680000 87f0792a 00000000
[    3.560103] $ 4   : 87e810c0 7ffeff7f 00000020 00000000
[    3.565323] $ 8   : 00000040 87f07962 00000001 87c1ea80
[    3.570546] $12   : 810f2874 ffffff80 00000000 777462c0
[    3.575768] $16   : 806ad3c0 00000040 87e810c0 7ffeff7f
[    3.580991] $20   : 00000000 c0000000 00000020 87e90800
[    3.586213] $24   : 00001012 8002caa8                  
[    3.591435] $28   : 80526000 87c0dea0 806acf40 802b1d28
[    3.596661] Hi    : 00480e1d
[    3.599530] Lo    : aa3bbf71
[    3.602443] epc   : 803253a8 eth_type_trans+0x14/0x210
[    3.607566] ra    : 802b1d28 xrx200_poll_rx+0x134/0x1d8
[    3.612765] Status: 1100ff03 KERNEL EXL IE 
[    3.616944] Cause : 00800010 (ExcCode 04)
[    3.620948] BadVA : 7fff00b3
[    3.623817] PrId  : 00019556 (MIPS 34Kc)
[    3.627732] Modules linked in: dwc2 gpio_button_hotplug
[    3.632969] Process swapper/0 (pid: 0, threadinfo=80526000, task=805358f8, tls=00000000)
[    3.641049] Stack : 8110dd60 8053270c 00000000 00000001 806ad3c0 71000040 87e810c0 806ad3c0
          00000040 802b1d28 80530000 80074d18 8110dd60 8053270c 8000003f 804dfa30
          806ad3c0 00000020 8110de80 00000003 0000012c 87c0df28 fffede5f 80530000
          87c0df30 80305f58 00000001 80530000 804a0000 80074da0 80530000 804f5f28
          80530000 804f6278 87c0df28 87c0df28 87c0df30 87c0df30 8052804c 00000004
          ...
[    3.676560] Call Trace:
[    3.679015] [] eth_type_trans+0x14/0x210
[    3.683813] [] xrx200_poll_rx+0x134/0x1d8
[    3.688706] [] net_rx_action+0x13c/0x2f8
[    3.693472] [] __do_softirq+0x2d4/0x2ec
[    3.698170] [] irq_exit+0x94/0xc8
[    3.702364] [] plat_irq_dispatch+0xac/0xdc
[    3.707290] 
[    3.708766] 
Code: afb0001c  afbf0024  ac850014  00a08821  10400004  00808021  00802821  0040f809 
[    3.718772] ---[ end trace aa248b0e31160e28 ]---
[    3.726757] Kernel panic - not syncing: Fatal exception in interrupt
[    3.733705] Rebooting in 1 seconds..

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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=330#comment1609