My Thinkpad X1 gen 6 with Ubuntu 22.04, Lenovo 40AJ dock with 4K LG
monitor with DP cable, will sometimes just show 2 or 4 lines with "DPCD
read on addr 0x4b0 for 1 bytes NAKed", after which the system will just
continue to work. But sometimes the "1 bytes NAKed" messages just keep
running - which is when the session will crash, eventually.

If I connect the dock with the laptop LCD on, the "1 bytes NAKed" will
freeze the LCD. When I'm fast enough to disconnect the DP cable, the LCD
unfreezes. However, reconnecting the DP will re-freeze the LCD.

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1970495

Title:
  Window manager freezes when plugging in USB-C dock with external
  monitor ([drm] *ERROR* mstb 00000000f21f0a30 port 1: DPCD read on addr
  0x4b0 for 1 bytes NAKed)

Status in GNOME Shell:
  New
Status in linux package in Ubuntu:
  Confirmed
Status in mutter package in Ubuntu:
  Confirmed

Bug description:
  1. Problem DOES appear on Lenovo T470s (Intel).
  2. Problem DOES appear on Lenovo T14 Gen2 (AMD).
  3. Problem does NOT appear on either of the above *when in the Live 
Installer*.

  I specifically checked that my dock behaved well under the Live
  Installer before deciding to move my workstations to Jammy. Upon
  logging into a fresh Jammy install, I found the following problem
  behavior: When the dock is plugged in, the built-in display freezes
  and the dock-attached displays power up but never render anything (ie,
  they stay black). Unplugging the USB-C cable gets mouse/keyboard
  response back on the built-in display.

  ProblemType: Bug
  DistroRelease: Ubuntu 22.04
  Package: gnome-shell 42.0-2ubuntu1
  ProcVersionSignature: Ubuntu 5.15.0-27.28-generic 5.15.30
  Uname: Linux 5.15.0-27-generic x86_64
  ApportVersion: 2.20.11-0ubuntu82
  Architecture: amd64
  CasperMD5CheckResult: pass
  CurrentDesktop: ubuntu:GNOME
  Date: Tue Apr 26 18:32:35 2022
  DisplayManager: gdm3
  InstallationDate: Installed on 2022-04-26 (0 days ago)
  InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 
(20220419)
  ProcEnviron:
   TERM=xterm-256color
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  RelatedPackageVersions: mutter-common 42.0-3ubuntu2
  SourcePackage: gnome-shell
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/gnome-shell/+bug/1970495/+subscriptions


-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to