External display via Thunderbolt mobile dock detected but no signal

Steps to reproduce:

1. Connect docking station (Targus HD583) to ThinkPad laptop via USB-C/Thunderbolt, without connecting display.

2. Restart

3. Connect display to docking station using DisplayPort (HDMI behaves the same).

4. Switch to the external display if not automatic.

5. Sometimes works here this first time. I have a Lenovo display which usually works the first time after reboot but also a Dell display which I have never gotten to work.

6. Reconnect DP or Thunderbolt. Lenovo display has survived subsequent DP reconnects but never Thunderbolt reconnect. Once it fails, it always fails.

7. Display reacts but loses signal before anything is shown. Kernel log shows:

   kernel: i915 0000:00:02.0: [drm] *ERROR* [ENCODER:272:DDI TC3/PHY TC3][DPRX] Failed clock recovery 10 times, giving up!
   kernel: i915 0000:00:02.0: [drm] *ERROR* Link Training Unsuccessful

Attached are logs dumped after boot when the display worked. Another log dump from the same boot taken later after multiple reconnects when the display does not work.

logs.zip

logs.zip file list

display_has_signal
display_has_signal/dmesg.txt
display_has_signal/intel_reg_dump.txt
display_has_signal/intel_reg_dump.txt.stderr
display_has_signal/vbios.dump
display_has_signal/vbios.dump.stderr
display_lost_signal
display_lost_signal/dmesg.txt
display_lost_signal/intel_reg_dump.txt
display_lost_signal/intel_reg_dump.txt.stderr
display_lost_signal/vbios.dump
display_lost_signal/vbios.dump.stderr

Some related things that does work:

• A Windows 11 laptop with the same docking station and display.
• Direct HDMI connection (no DP connector to test with), bypassing the docking station.
• Display's own Thunderbolt connection.

System attribute	value
System architecture	x86_64
Kernel version	6.2.0-rc4-1-drm-tip-git-g7d3e7f64a42d
Linux distribution	Arch Linux
Machine or motherboard model	Lenovo ThinkPad T14 Gen 3 21AHS0DK00
Display connector	DP, HDMI