Comment 27 for bug 1857385

Lenovo X1 Extreme Gen2
Docking Lenovo Thunderbolt 3 Gen2

Was getting similar random disconnects every 2-5 minutes:

[125028.443102] pcieport 0000:05:01.0: pciehp: Slot(1): Link Down
[125028.443108] pcieport 0000:05:01.0: pciehp: Slot(1): Card not present
[125028.443122] pcieport 0000:08:04.0: can't change power state from D3cold to D0 (config space inaccessible)
[125028.444133] xhci_hcd 0000:09:00.0: remove, state 1
[125028.444151] usb usb6: USB disconnect, device number 1
[125028.444156] usb 6-2: USB disconnect, device number 2
[125028.444162] usb 6-2.1: USB disconnect, device number 3
[125028.444167] usb 6-2.1.2: USB disconnect, device number 5
[125028.444369] xhci_hcd 0000:09:00.0: xHCI host controller not responding, assume dead
..
.

Fixed by connecting two power supplies to both laptop and docking (2x135W).