[Focal] No HDMI output through thunderbolt docking station

[Gavin Lin]

I can find monitor in display list, but no output from it.
Also, I can't switch to extend mode, it failed to apply the setting and switched back to mirror mode.

[Steps]
1. Connect a thunderbolt docking station to thunderbolt port.
2. Connect HDMI monitor to HDMI port on the docking station.
3. Switch mode in display setting

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27
Uname: Linux 5.4.0-21-generic x86_64
ApportVersion: 2.20.11-0ubuntu25
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 10 16:44:40 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation UHD Graphics 620 (Whiskey Lake) [8086:3ea0] (prog-if 00 [VGA controller])
   Subsystem: Dell UHD Graphics 620 (Whiskey Lake) [1028:08af]
InstallationDate: Installed on 2020-04-09 (1 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200402)
MachineType: Dell Inc. XPS 13 9380
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-21-generic root=UUID=98c0c28f-278e-442b-8fc9-6d663bacd68d ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/08/2019
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.1.1
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.1.1:bd01/08/2019:svnDellInc.:pnXPS139380:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 13 9380
dmi.product.sku: 08AF
dmi.sys.vendor: Dell Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.100-4
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.7-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

Please try logging in to 'Ubuntu on Wayland' and tell us if that avoids the bug.

[Cyrus Lien (cyruslien)]

@Gavin,
Would you please try the drm-tip kernel with drm debug option "drm.debug=0xe log_buf_len=4M" ?
Also, please provide the output of `fwupdmgr get-devices`.

[Cyrus Lien (cyruslien)]

The issue only reproduced on first thunderbolt port which next to escape key.
The external monitor doesn't lit up even though xrandr shows it is connected.
Switching output modes by hotkey or GUI doesn't help.

xrandr output:
...
DP-2-3 connected 1920x1080+0+0
...

[Cyrus Lien (cyruslien)]

Can not reproduce the issue with drm-tip kernel (#3).

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Timo Aaltonen (tjaalton)]

seems to be the same with a 'Cable Matters' tb-dock with displayport hooked to a 4k screen, only mirrored output works

[Timo Aaltonen (tjaalton)]

could you test mainline builds 5.5..5.6?