Comment 6 for bug 1825395

Attaching dmesg showing failed thunderbolt attachment. There is a good hotplug starting with

[35304.659358] thunderbolt 0-1: new device found, vendor=0x108 device=0x1630
[35304.659361] thunderbolt 0-1: Lenovo ThinkPad Thunderbolt 3 Dock

for example, you can see that the system discovers the downstream USB controller and USB audio device that is part of the dock:

[35305.406824] xhci_hcd 0000:0b:00.0: xHCI Host Controller
[35305.406831] xhci_hcd 0000:0b:00.0: new USB bus registered, assigned bus number 3
...
[35306.102685] usb 3-1: New USB device found, idVendor=17ef, idProduct=306a, bcdDevice=28.00
[35306.102688] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[35306.102691] usb 3-1: Product: ThinkPad Thunderbolt 3 Dock USB Audio

then there are a few suspend/resume cycles, and a second hotplug of the thunderbolt dock:

[40222.796009] thunderbolt 0-1: new device found, vendor=0x108 device=0x1630
[40222.796010] thunderbolt 0-1: Lenovo ThinkPad Thunderbolt 3 Dock

in this case PCI bus enumeration seems to fail:

[40223.479357] pci 0000:0a:00.0: devices behind bridge are unusable because [bus 0b] cannot be assigned for them
[40223.479371] pci 0000:09:00.0: devices behind bridge are unusable because [bus 0a] cannot be assigned for them
[40223.479397] pci 0000:0a:00.0: devices behind bridge are unusable because [bus 0b] cannot be assigned for them
[40223.479411] pcieport 0000:07:02.0: bridge has subordinate 0a but max busn 0b
[40223.479459] pci_bus 0000:3d: busn_res: can not insert [bus 3d-70] under [bus 07-0b] (conflicts with (null) [bus 07-0b])
[40223.479462] pcieport 0000:07:04.0: PCI bridge to [bus 3d-70]
[40223.479470] pcieport 0000:07:04.0: bridge window [mem 0xd4000000-0xe9ffffff]
[40223.479475] pcieport 0000:07:04.0: bridge window [mem 0x90000000-0xb9ffffff 64bit pref]
[40223.479476] pcieport 0000:07:04.0: devices behind bridge are unusable because [bus 3d-70] cannot be assigned for them