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brc192

Member

Registered: 2016-05-27

Posts: 2

Razer Core X Chroma eGPU - Ethernet dies with xhci_hcd errors

I have a Razer 2018 Stealth with the Razer Core X Chroma eGPU running an Nvidia 1080ti. The eGPU comes equipped with 4 USB 3.0 slots as well as an Ethernet port. After using Firefox for 1-2 minutes, my Ethernet connection dies, and Network Manager fails to reconnect. For reference, all of my other USB ports remain working correctly (mouse, keyboard, external SSDs). I am also able to use the GPU without any problems, running dual monitors and having tested several different games.

As soon as it fails, the following errors are present in my journalctl:

[  506.957587] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  506.957590] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078960 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  507.242935] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  507.242940] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078970 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  507.785552] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  507.785555] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078980 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  508.841763] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  508.841767] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078990 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  510.994757] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  510.994760] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789a0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  511.145711] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  511.145717] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789b0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  511.636962] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  511.636967] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789c0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  512.009453] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  512.009457] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789d0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  512.506672] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  512.506676] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789e0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  512.648261] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  512.648277] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a90789f0 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  513.023201] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  513.023205] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078a00 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  513.518301] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  513.518306] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078a10 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  513.662192] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  513.662202] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078a20 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  514.035328] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  514.035332] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078a30 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  514.532266] xhci_hcd 0000:0d:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 4 comp_code 13
[  514.532269] xhci_hcd 0000:0d:00.0: Looking for event-dma 00000004a9078a40 trb-start 00000004a9078940 trb-end 00000004a9078940 seg-start 00000004a9078000 seg-end 00000004a9078ff0
[  588.790502] ax88179_178a 10-1:1.0 ens4u1: ax88179 - Link status is: 0

From this point on, my Ethernet refuses to reconnect in network manager, with the following errors in journalctl:

Apr 17 01:53:54 NetworkManager[817]: <warn>  [1587102834.3198] dhcp4 (ens4u1): request timed out
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3198] dhcp4 (ens4u1): state changed unknown -> timeout
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3198] device (ens4u1): state change: ip-config -> failed (reason 'ip-config-unavailable>
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3201] manager: NetworkManager state is now DISCONNECTED
Apr 17 01:53:54 NetworkManager[817]: <warn>  [1587102834.3205] device (ens4u1): Activation: failed for connection 'Wired connection 2'
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3207] device (ens4u1): state change: failed -> disconnected (reason 'none', sys-iface-s>
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3331] dhcp4 (ens4u1): canceled DHCP transaction
Apr 17 01:53:54 NetworkManager[817]: <info>  [1587102834.3331] dhcp4 (ens4u1): state changed timeout -> done

Some other information:

$ lspci -nn

00:00.0 Host bridge [0600]: Intel Corporation Coffee Lake HOST and DRAM Controller [8086:3e34] (rev 0c)
00:02.0 VGA compatible controller [0300]: Intel Corporation UHD Graphics 620 (Whiskey Lake) [8086:3ea0] (rev 02)
00:04.0 Signal processing controller [1180]: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem [8086:1903] (rev 0c)
00:12.0 Signal processing controller [1180]: Intel Corporation Cannon Point-LP Thermal Controller [8086:9df9] (rev 30)
00:14.0 USB controller [0c03]: Intel Corporation Cannon Point-LP USB 3.1 xHCI Controller [8086:9ded] (rev 30)
00:14.2 RAM memory [0500]: Intel Corporation Cannon Point-LP Shared SRAM [8086:9def] (rev 30)
00:14.3 Network controller [0280]: Intel Corporation Cannon Point-LP CNVi [Wireless-AC] [8086:9df0] (rev 30)
00:15.0 Serial bus controller [0c80]: Intel Corporation Cannon Point-LP Serial IO I2C Controller #0 [8086:9de8] (rev 30)
00:15.1 Serial bus controller [0c80]: Intel Corporation Cannon Point-LP Serial IO I2C Controller #1 [8086:9de9] (rev 30)
00:16.0 Communication controller [0780]: Intel Corporation Cannon Point-LP MEI Controller #1 [8086:9de0] (rev 30)
00:1c.0 PCI bridge [0604]: Intel Corporation Cannon Point-LP PCI Express Root Port #1 [8086:9db8] (rev f0)
00:1c.4 PCI bridge [0604]: Intel Corporation Cannon Point-LP PCI Express Root Port #5 [8086:9dbc] (rev f0)
00:1d.0 PCI bridge [0604]: Intel Corporation Cannon Point-LP PCI Express Root Port #9 [8086:9db0] (rev f0)
00:1d.4 PCI bridge [0604]: Intel Corporation Cannon Point-LP PCI Express Root Port #13 [8086:9db4] (rev f0)
00:1f.0 ISA bridge [0601]: Intel Corporation Cannon Point-LP LPC Controller [8086:9d84] (rev 30)
00:1f.3 Audio device [0403]: Intel Corporation Cannon Point-LP High Definition Audio Controller [8086:9dc8] (rev 30)
00:1f.4 SMBus [0c05]: Intel Corporation Cannon Point-LP SMBus Controller [8086:9da3] (rev 30)
00:1f.5 Serial bus controller [0c80]: Intel Corporation Cannon Point-LP SPI Controller [8086:9da4] (rev 30)
03:00.0 PCI bridge [0604]: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016] [8086:15da] (rev 02)
04:00.0 PCI bridge [0604]: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016] [8086:15da] (rev 02)
04:01.0 PCI bridge [0604]: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016] [8086:15da] (rev 02)
04:02.0 PCI bridge [0604]: Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016] [8086:15da] (rev 02)
05:00.0 System peripheral [0880]: Intel Corporation JHL6340 Thunderbolt 3 NHI (C step) [Alpine Ridge 2C 2016] [8086:15d9] (rev 02)
06:00.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
07:01.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
07:04.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
08:00.0 VGA compatible controller [0300]: NVIDIA Corporation GP102 [GeForce GTX 1080 Ti] [10de:1b06] (rev a1)
08:00.1 Audio device [0403]: NVIDIA Corporation GP102 HDMI Audio Controller [10de:10ef] (rev a1)
09:00.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
0a:00.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
0a:01.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
0a:02.0 PCI bridge [0604]: Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016] [8086:15d3] (rev 02)
0b:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM1142 USB 3.1 Host Controller [1b21:1242]
0c:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM1142 USB 3.1 Host Controller [1b21:1242]
0d:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM1142 USB 3.1 Host Controller [1b21:1242]
3b:00.0 USB controller [0c03]: Intel Corporation JHL6340 Thunderbolt 3 USB 3.1 Controller (C step) [Alpine Ridge 2C 2016] [8086:15db] (rev 02)
3c:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983 [144d:a808]

$ lsusb

Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 009 Device 003: ID 1532:0f1a Razer USA, Ltd Razer Core X Chroma
Bus 009 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 010 Device 002: ID 0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet
Bus 010 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 003: ID 1532:021e Razer USA, Ltd Razer Ornata Chroma
Bus 007 Device 002: ID 046d:c07d Logitech, Inc. G502 Mouse
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge, ASM1053E SATA 6Gb/s bridge, ASM1153 SATA 3Gb/s bridge, ASM1153E SATA 6Gb/s bridge
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 1532:0239 Razer USA, Ltd Razer Blade
Bus 001 Device 002: ID 13d3:56d5 IMC Networks Integrated Camera
Bus 001 Device 004: ID 8087:0aaa Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Any help would be appreciated at this point. I am able to get Ethernet working with an additional adapter, but I would like to be able to use the one built into my eGPU. My WiFi also works without any problems. I have seen several posts from 2-3 years ago referencing similar xhci_hcd error messages, but it doesn't seem any directly apply to my situation.

Wolfizen

Member

Registered: 2015-10-02

Posts: 2

Re: Razer Core X Chroma eGPU - Ethernet dies with xhci_hcd errors

I get the same behavior . Works fine for 5-10 minutes after being connected then dies.

Wolfizen

Member

Registered: 2015-10-02

Posts: 2

Re: Razer Core X Chroma eGPU - Ethernet dies with xhci_hcd errors

I fixed it! There is a driver package for the specific Ethernet card used in the Razer Core X models. The card is an "ASIX AX88179" and the driver package is `asix-ax88179-dkms` (AUR). It completely solved the disconnection issue. EDIT: It helps but it still dies sometimes. It seems to be doing it less often though.

Last edited by Wolfizen (2020-08-31 16:16:50)

andrej.podzimek

Member

From: Zürich, Switzerland

Registered: 2005-04-10

Posts: 115

Re: Razer Core X Chroma eGPU - Ethernet dies with xhci_hcd errors

I fixed it! There is a driver package for the specific Ethernet card used in the Razer Core X models. The card is an "ASIX AX88179" and the driver package is `asix-ax88179-dkms` (AUR). It completely solved the disconnection issue. EDIT: It helps but it still dies sometimes. It seems to be doing it less often though.

In some sense the "fix" is worse than the in-kernel driver. When I want to unplug the Razer X Chroma, starting by unloading the NVidia driver, it works fine with the in-kernel driver, but wreaks havoc with the one from AUR:

Dec 11 16:38:10 charon kernel: ------------[ cut here ]------------
Dec 11 16:38:10 charon kernel: NETDEV WATCHDOG: charon1gcore (ax88179_178a): transmit queue 0 timed out
Dec 11 16:38:10 charon kernel: WARNING: CPU: 27 PID: 0 at net/sched/sch_generic.c:442 dev_watchdog+0x254/0x260
Dec 11 16:38:10 charon kernel: Modules linked in: ax88179_178a(OE) ecb ecryptfs rfcomm ccm nls_iso8859_1 nls_cp437 vfat fat raid1 md_mod nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct squashfs nft_nat cmac algif_hash algif_skcipher af_alg bnep loop nft_chain_nat n>
Dec 11 16:38:10 charon kernel:  soundcore i2c_piix4 zenpower(OE) cfg80211 igb thunderbolt tpm_crb macsec crc_itu_t dca rfkill wmi evdev tpm_tis tpm_tis_core mac_hid pinctrl_amd acpi_cpufreq vboxnetflt(OE) vboxnetadp(OE) vboxdrv(OE) usbip_host usbip_core msr sg crypto_user fuse ip_>
Dec 11 16:38:10 charon kernel: CPU: 27 PID: 0 Comm: swapper/27 Tainted: P           OE     5.9.13-arch1-1-zen2 #1
Dec 11 16:38:10 charon kernel: Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X570 Creator, BIOS P3.10 10/28/2020
Dec 11 16:38:10 charon kernel: RIP: 0010:dev_watchdog+0x254/0x260
Dec 11 16:38:10 charon kernel: Code: 31 56 79 ff eb 87 4c 89 f7 c6 05 b5 fa 0c 01 01 e8 e1 ad fa ff 44 89 e9 4c 89 f6 48 c7 c7 20 64 20 98 48 89 c2 e8 50 f1 15 00 <0f> 0b e9 65 ff ff ff 0f 1f 44 00 00 0f 1f 44 00 00 41 54 48 8d 87
Dec 11 16:38:10 charon kernel: RSP: 0018:ffffb3e3808c0e90 EFLAGS: 00010286
Dec 11 16:38:10 charon kernel: RAX: 0000000000000000 RBX: ffff89656494a600 RCX: 0000000000000000
Dec 11 16:38:10 charon kernel: RDX: 0000000000000103 RSI: ffffffff98159caf RDI: 00000000ffffffff
Dec 11 16:38:10 charon kernel: RBP: ffff896940201480 R08: 0000000000000001 R09: 0000000000000d16
Dec 11 16:38:10 charon kernel: R10: 0000000000000004 R11: 0000000000000000 R12: ffff8969402013dc
Dec 11 16:38:10 charon kernel: R13: 0000000000000000 R14: ffff896940201000 R15: ffff89656494a680
Dec 11 16:38:10 charon kernel: FS:  0000000000000000(0000) GS:ffff896c8f0c0000(0000) knlGS:0000000000000000
Dec 11 16:38:10 charon kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Dec 11 16:38:10 charon kernel: CR2: 00003d1144d9c000 CR3: 0000801c237ac000 CR4: 0000000000350ee0
Dec 11 16:38:10 charon kernel: Call Trace:
Dec 11 16:38:10 charon kernel:  <IRQ>
Dec 11 16:38:10 charon kernel:  ? pfifo_fast_init+0x100/0x100
Dec 11 16:38:10 charon kernel:  ? pfifo_fast_init+0x100/0x100
Dec 11 16:38:10 charon kernel:  call_timer_fn+0x2d/0x160
Dec 11 16:38:10 charon kernel:  ? pfifo_fast_init+0x100/0x100
Dec 11 16:38:10 charon kernel:  __run_timers+0x1ea/0x280
Dec 11 16:38:10 charon kernel:  run_timer_softirq+0x2b/0x50
Dec 11 16:38:10 charon kernel:  __do_softirq+0xfd/0x342
Dec 11 16:38:10 charon kernel:  asm_call_irq_on_stack+0x12/0x20
Dec 11 16:38:10 charon kernel:  </IRQ>
Dec 11 16:38:10 charon kernel:  do_softirq_own_stack+0x5d/0x80
Dec 11 16:38:10 charon kernel:  irq_exit_rcu+0xd8/0x120
Dec 11 16:38:10 charon kernel:  sysvec_apic_timer_interrupt+0x47/0xe0
Dec 11 16:38:10 charon kernel:  asm_sysvec_apic_timer_interrupt+0x12/0x20
Dec 11 16:38:10 charon kernel: RIP: 0010:cpuidle_enter_state+0xc4/0x380
Dec 11 16:38:10 charon kernel: Code: 42 80 a5 68 e8 2d b8 90 ff 49 89 c7 0f 1f 44 00 00 31 ff e8 2e c6 90 ff f6 44 24 0f 01 0f 85 e9 01 00 00 fb 66 0f 1f 44 00 00 <45> 85 e4 0f 88 34 01 00 00 4c 2b 3c 24 49 63 c4 48 6b d0 68 48 6b
Dec 11 16:38:10 charon kernel: RSP: 0018:ffffb3e38023fea0 EFLAGS: 00000246
Dec 11 16:38:10 charon kernel: RAX: ffff896c8f0c0000 RBX: ffff896c7bb52400 RCX: 000000000000001f
Dec 11 16:38:10 charon kernel: RDX: 0000000000000000 RSI: ffffffff98159caf RDI: ffffffff98164369
Dec 11 16:38:10 charon kernel: RBP: ffffffff986d4140 R08: 000001e3268683f7 R09: 0000000000000018
Dec 11 16:38:10 charon kernel: R10: 00000000000000b7 R11: 00000000000002b8 R12: 0000000000000001
Dec 11 16:38:10 charon kernel: R13: ffffffff986d41c0 R14: 0000000000000001 R15: 000001e3268683f7
Dec 11 16:38:10 charon kernel:  cpuidle_enter+0x29/0x40
Dec 11 16:38:10 charon kernel:  do_idle+0x1ed/0x280
Dec 11 16:38:10 charon kernel:  cpu_startup_entry+0x19/0x20
Dec 11 16:38:10 charon kernel:  secondary_startup_64+0xb6/0xc0
Dec 11 16:38:10 charon kernel: ---[ end trace b765e58353ecd77a ]---

Dec 11 16:38:15 charon kernel: xhci_hcd 0000:42:00.0: xHCI host not responding to stop endpoint command.
Dec 11 16:38:15 charon kernel: xhci_hcd 0000:42:00.0: USBSTS:
Dec 11 16:38:15 charon kernel: xhci_hcd 0000:42:00.0: xHCI host controller not responding, assume dead
Dec 11 16:38:15 charon kernel: xhci_hcd 0000:42:00.0: HC died; cleaning up
Dec 11 16:38:15 charon kernel: usb 15-2: USB disconnect, device number 3
Dec 11 16:38:15 charon kernel: usb 16-1: USB disconnect, device number 2
Dec 11 16:38:15 charon kernel: ax88179_178a 16-1:1.0 charon1gcore: unregister 'ax88179_178a' usb-0000:42:00.0-1, 
Dec 11 16:38:15 charon kernel: ax88179_178a 16-1:1.0 charon1gcore: Failed to read reg index 0x0002: -19
Dec 11 16:38:15 charon kernel: ax88179_178a 16-1:1.0 charon1gcore: Failed to write reg index 0x0002: -19
Dec 11 16:38:16 charon kernel: ax88179_178a 16-1:1.0 charon1gcore (unregistered): Failed to write reg index 0x0002: -19
Dec 11 16:38:16 charon kernel: ax88179_178a 16-1:1.0 charon1gcore (unregistered): Failed to write reg index 0x0001: -19
Dec 11 16:38:16 charon kernel: ax88179_178a 16-1:1.0 charon1gcore (unregistered): Failed to write reg index 0x0002: -19
Dec 11 16:38:16 charon kernel: xhci_hcd 0000:42:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0033 address=0xf5748040 flags=0x0020]
Dec 11 16:38:17 charon kernel: xhci_hcd 0000:42:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0033 address=0xf5740040 flags=0x0020]
Dec 11 16:38:18 charon kernel: xhci_hcd 0000:42:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0033 address=0xf5738040 flags=0x0020]
Dec 11 16:38:18 charon kernel: xhci_hcd 0000:42:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0033 address=0xf5730040 flags=0x0020]
Dec 11 16:38:19 charon kernel: xhci_hcd 0000:42:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0033 address=0xf5728040 flags=0x0020]

This^^^ was not the eGPU disconnecting, it was all caused by merely unloading the NVidia modules.

On the other hand, with the default in-kernel driver I had a much more serious mishap, which struck after I unloaded and reloaded the ax88179_178a module a couple of times (to restore normal function of the network). But it seems so implausible to be (causally) related that I won't speculate about it at this point, until and unless it happens again. (It may have been just pure coincidence with another failure.)