This is the closest match I could find to the problem I'm experiencing. Every Kernel update above 5.4.0-59-generic on Ubuntu 20.04.1 LTS on this Thinkpad T580 docked on the Thinkpad Ultra Docking Station causes the computer to freeze up either just before the login screen, on the login screen or shortly after successful login. If I take the machine off of the docking station, everything works fine. Docking and removing external monitor connections does not make it any better.
Sorry if I'm not in compliance with this forum's practices. I'll go read-up on that and get in line ASAP. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-oem-5.6 in Ubuntu. https://bugs.launchpad.net/bugs/1902469 Title: drm/i915/dp_mst - System would hang during the boot up. Status in linux package in Ubuntu: Fix Released Status in linux-oem-5.6 package in Ubuntu: Invalid Status in linux source package in Focal: Invalid Status in linux-oem-5.6 source package in Focal: Fix Released Status in linux source package in Groovy: Fix Released Bug description: [Impact] The machine connect with the external monitor on dock(Thunderbolt), Then system would hang during the boot-up. [Fix] The atomic check hooks must look up the encoder to be used with a connector from the connector's atomic state, and not assume that it's the connector's current attached encoder. The latter one can change under the atomic check func, or can be unset yet as in the case of MST connectors. [test] With the patch, The machine connect with the external monitor on dock(Thunderbolt), Then system boot up successfully. [Regression Potential] Low. This patch is also verified by others and is archived in the drmtip. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1902469/+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
