Thanks for the response. There is quite a lot going on here. First off - The XPS 9570 is a CFL system.
The going black in the first place is an artifact what fwupd does to query the firmware on the MST hubs in the dock. What it does is "wakes" the MST hubs by putting them into a higher power mode. When in this mode 1-2 "fake monitors" shows up in DPCD of the DP aux channel. This allows applications such as fwupd to interact with the monitor. The flicker and going black is the i915 driver probing those "fake" monitors. To me this is all expected behavior thus far. Something that (I think?) might help is if the graphics drivers can blacklist the EDID associated with the fake monitors to prevent re- probing them but still letting communication with them work for fwupd. That needs to be discussed with the Intel graphics folks to see if that's a possibility. If it's not, then we have to have a tradeoff of no version is registered with fwupd when no (or not enough) monitors are plugged into the dock. Now with 4.19, the staying black sounds like a separate graphics driver bug. It might be useful if you can test with drm-tip and still reproduce that. if so, then this is worth reporting to Intel's graphics bugzilla to investigate. The USB not working, I would wonder if it's actually an artifact of the above bug. Userspace is hung and so bolt isn't authorizing the thunderbolt device meaning USB won't work. ** Also affects: linux (Ubuntu) Importance: Undecided Status: New ** Changed in: fwupd (Ubuntu) Status: New => Triaged ** Changed in: fwupd (Ubuntu) Importance: Undecided => Medium -- 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/1806323 Title: libfu_plugin_dell.so w/dell TB16 Dock blanks the display Status in fwupd package in Ubuntu: Triaged Status in linux package in Ubuntu: New Bug description: Absolutely reproducible in Ubuntu 18.04.1 Gnome 3 UI with a Dell XP15 laptop and a Dell TB16 dock. A few seconds after logging into the Gnome 3 UI, something in the UI starts the fwupd.service. About 2 seconds later, the display goes blank and does not come back. There is no obvious recovery short of killing all the user's processes, and then logging back in. A second login does not reproduce the problem, since the fwupd service is now running, and does not restart. However manually restarting the fwupd service causes the problem to recur. The problem does not occur if the "dell" module is blacklisted in /etc/fwupd/daemon.conf. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: fwupd 1.0.6-2 ProcVersionSignature: Ubuntu 4.15.0-39.42-generic 4.15.18 Uname: Linux 4.15.0-39-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.5 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sun Dec 2 22:02:31 2018 InstallationDate: Installed on 2018-11-19 (13 days ago) InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725) SourcePackage: fwupd UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.fwupd.daemon.conf: 2018-12-02T21:41:51.195270 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fwupd/+bug/1806323/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : email@example.com Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp