Thunderbolt display not detected

[Max Richter]

I am using a Dell XPS 13 (9370) connected to a Caldigit TS3 Plus thunderbolt dock. On this dock I have two monitors connected. One is connected to the display port of the dock, the second one is connected to an USB-C Thunderbolt port using an USB-C to mini DP adapter.

The second monitor is only detected, when I _first_ plug in the adapter and _then_ plug in the the cable to the adapter. This also only works when the system has booted _and_ I am logged in. I already disabled thunderbolt security completely in UEFI. Once the monitor has been detected it is also working during boot, when I restart the system.
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ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: max 1628 F...m pulseaudio
 /dev/snd/controlC0: max 1628 F.... pulseaudio
 /dev/snd/controlC1: max 1628 F.... pulseaudio
CurrentDesktop: X-Cinnamon
DistroRelease: Linux Mint 19.1
HibernationDevice: RESUME=UUID=e6ab437d-a79f-412f-bed4-1a80bbde0736
InstallationDate: Installed on 2019-01-05 (47 days ago)
InstallationMedia: Linux Mint 19.1 "Tessa" - Release amd64 20181217
MachineType: Dell Inc. XPS 13 9370
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-45-generic root=/dev/mapper/mint--vg-root ro quiet splash vt.handoff=1
ProcVersionSignature: Ubuntu 4.15.0-45.48-generic 4.15.18
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-45-generic N/A
 linux-backports-modules-4.15.0-45-generic N/A
 linux-firmware 1.173.3
Tags: tessa
Uname: Linux 4.15.0-45-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip docker lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 11/04/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.6.3
dmi.board.name: 09DKKT
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.6.3:bd11/04/2018:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn09DKKT:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 13 9370
dmi.sys.vendor: Dell Inc.

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

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1817070

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Max Richter (maxrichter)]

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[Kai-Heng Feng (kaihengfeng)]

Seems like Caldigit TS3 Plus has a front USB-C port. Does this issue happen when using that port instead of Thunderbolt port?

[Max Richter (maxrichter)]

I don't this is going to work, as this port is for data only and not for displays

[Kai-Heng Feng (kaihengfeng)]

Ok. Please try latest DRM kernel here:
https://kernel.ubuntu.com/~kernel-ppa/mainline/drm-tip/2019-02-21/

If it doesn't solve the issue, please file an upstream bug report so Intel graphics folks can work on this:
https://bugs.freedesktop.org/
Product: DRI
Component: DRM/Intel

[Max Richter (maxrichter)]

Ok tried with new kernel but no change. I also figured out this is nit related to the dock. Behaves the same when I connect the adapter directly to thunderbolt port on the laptop. Order matters here as well. First adapter, then cable :).
I will then create a bug for Intel graphics.

[Max Richter (maxrichter)]

@kaihengfeng Might this also be an USB issue? It seems to me that the root cause is somewhere in the order the USB-C to miniDP is detected. Does it make sense to post the issue there?

[Kai-Heng Feng (kaihengfeng)]

Yes, please do. Intel Graphics folks know better than me.

[Daniel van Vugt (vanvugt)]

Maybe related:

https://gitlab.gnome.org/GNOME/mutter/issues/728