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