Comment 78 for bug 1860284

I'm also affected by this bug on 20.04 with the HWE 5.13 kernel (currently: 5.13.0-30-generic #33~20.04.1-Ubuntu SMP Mon Feb 7 14:25:10 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux). My PCIe Thunderbolt card (ASUS ThunderboltEX 4, Intel JHL8540 controller) only partially works: the USB part works and USB devices plugged into the dock are recognised and functional (including the dock's built-in Ethernet interface), however there is no video signal coming from the dock's DisplayPort ports. I've tried the patch mentioned in the kernel bug tracker [1], but it doesn't fix the issue.

Possibly relevant kernel messages:
[ 0.602662] pci 0000:38:00.0: BAR 1: assigned to efifb
[ 0.629016] pci 0000:02:00.0: BAR 13: no space for [io size 0x2000]
[ 0.629017] pci 0000:02:00.0: BAR 13: failed to assign [io size 0x2000]
[ 0.629019] pci 0000:02:00.0: BAR 13: no space for [io size 0x2000]
[ 0.629020] pci 0000:02:00.0: BAR 13: failed to assign [io size 0x2000]
[ 0.629021] pci 0000:03:00.0: BAR 13: no space for [io size 0x2000]
[ 0.629022] pci 0000:03:00.0: BAR 13: failed to assign [io size 0x2000]
[ 0.629023] pci 0000:03:00.0: BAR 13: no space for [io size 0x2000]
[ 0.629024] pci 0000:03:00.0: BAR 13: failed to assign [io size 0x2000]
[ 0.629026] pci 0000:04:01.0: BAR 13: no space for [io size 0x1000]
[ 0.629027] pci 0000:04:01.0: BAR 13: failed to assign [io size 0x1000]
[ 0.629028] pci 0000:04:03.0: BAR 13: no space for [io size 0x1000]
[ 0.629029] pci 0000:04:03.0: BAR 13: failed to assign [io size 0x1000]
[ 0.629030] pci 0000:04:03.0: BAR 13: no space for [io size 0x1000]
[ 0.629031] pci 0000:04:03.0: BAR 13: failed to assign [io size 0x1000]
[ 0.629032] pci 0000:04:01.0: BAR 13: no space for [io size 0x1000]
[ 0.629033] pci 0000:04:01.0: BAR 13: failed to assign [io size 0x1000]
[ 4.271107] thunderbolt 0000:05:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000e address=0xcb0f6500 flags=0x0020]
[ 25.977578] thunderbolt 0000:05:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000e address=0xcb0f6600 flags=0x0020]
[ 46.457436] thunderbolt 0000:05:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000e address=0xcb0f6700 flags=0x0020]
[ 66.937458] thunderbolt 0000:05:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000e address=0xcb0f6800 flags=0x0020]
[ 87.413107] thunderbolt 0000:05:00.0: failed to send driver ready to ICM
[ 87.414436] thunderbolt: probe of 0000:05:00.0 failed with error -110

[1] https://<email address hidden>/