Bug#1033637: linux-image-amd64: amdgpu - External displays connected through Thinkpad Ultra Dock not turn on after suspend

[Stefan K <shadow_7@gmx.net>]

Package: linux-image-amd64
Version: 6.1.15-1
Severity: important
X-Debbugs-Cc: shadow_7@gmx.net

Dear Maintainer,

I upgraded from Debian 11 to 12, since the upgrade I had this problems,
before it works fine (used Backports-Kernel).
I've connected 2 external Monitor via DisplayPort on a Thinkpad Ultra
Docking station and it happens often (not always) that the Monitor
doesn't wake up after suspend. In the KDE display settings I still see
external monitors. DRM said they are on:
grep . /sys/class/drm/card*-*/dpms
/sys/class/drm/card0-DP-1/dpms:Off
/sys/class/drm/card0-DP-2/dpms:Off
/sys/class/drm/card0-DP-3/dpms:Off
/sys/class/drm/card0-DP-6/dpms:On
/sys/class/drm/card0-DP-7/dpms:On
/sys/class/drm/card0-eDP-1/dpms:Off
/sys/class/drm/card0-HDMI-A-1/dpms:Off

and syslog said:
[drm:dc_link_allocate_mst_payload [amdgpu]] *ERROR* Failure: pbn_per_slot==0 not allowed. Cannot continue, returning DC_UNSUPPORTED_VALUE.

It's a Lenovo Thinkpad T14 Gen2 with AMD
AMD Ryzen 7 PRO 5850U with Radeon Graphics
lspci -nnk -d ::0300
08:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [1002:1638] (rev d1)
        Subsystem: Lenovo Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [17aa:5094]
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu


-- System Information:
Debian Release: 12.0
  APT prefers testing-security
  APT policy: (500, 'testing-security'), (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.1.0-6-amd64 (SMP w/16 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_US.UTF-8), LANGUAGE=de:en_US
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages linux-image-amd64 depends on:
ii  linux-image-6.1.0-6-amd64  6.1.15-1

linux-image-amd64 recommends no packages.

linux-image-amd64 suggests no packages.

-- no debconf information