REGRESSION: only one displayport fron docking station is used at a time

[neclepsio]

When my HP 840 G3 is connected to its docking station only one DisplayPort is used at a time. If I disconnect the one in use, the other is enabled. Only one display is detected. I'm using a fresh installation of Ubuntu 18.10. Before, on 18.04, it worked.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: xorg 1:7.7+19ubuntu8
ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
Uname: Linux 4.18.0-10-generic x86_64
ApportVersion: 2.20.10-0ubuntu13
Architecture: amd64
BootLog: Error: [Errno 13] Permesso negato: '/var/log/boot.log'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sat Nov 10 12:49:30 2018
DistUpgraded: Fresh install
DistroCodename: cosmic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Skylake GT2 [HD Graphics 520] [8086:1916] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Skylake GT2 [HD Graphics 520] [103c:8079]
InstallationDate: Installed on 2018-11-01 (9 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 004: ID 04ca:7054 Lite-On Technology Corp.
 Bus 001 Device 003: ID 8087:0a2b Intel Corp.
 Bus 001 Device 002: ID 03f0:521d Hewlett-Packard
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: HP HP EliteBook 840 G3
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-10-generic root=UUID=1203967d-3709-4fd4-966f-4c08b53203ce ro quiet splash vt.handoff=1
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/08/2017
dmi.bios.vendor: HP
dmi.bios.version: N75 Ver. 01.16
dmi.board.name: 8079
dmi.board.vendor: HP
dmi.board.version: KBC Version 85.76
dmi.chassis.asset.tag: 5CG7320Q91
dmi.chassis.type: 10
dmi.chassis.vendor: HP
dmi.modalias: dmi:bvnHP:bvrN75Ver.01.16:bd06/08/2017:svnHP:pnHPEliteBook840G3:pvr:rvnHP:rn8079:rvrKBCVersion85.76:cvnHP:ct10:cvr:
dmi.product.family: 103C_5336AN HP EliteBook
dmi.product.name: HP EliteBook 840 G3
dmi.product.sku: L3C65AV
dmi.sys.vendor: HP
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.95-1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.2-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.1-3ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-3

[Daniel van Vugt (vanvugt)]

Can you please try logging into "Ubuntu on Wayland" and tell us if the problem still occurs there?

[neclepsio (neclepsio)]

The problem also occurs in Wayland.

Ps: I tried to follow https://wiki.ubuntu.com/Bugs/FindRightPackage, maybe it needs to be updated?

[Daniel van Vugt (vanvugt)]

Thanks. In that case it can't be a Xorg bug so reassigning to the kernel.

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

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.20 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.20-rc2

[neclepsio (neclepsio)]

The last kernel does not fix, I added the tag but I cannot mark it as confirmed.

[neclepsio (neclepsio)]

I can add an important information to this bug. If the laptop lid is open, I can correctly manage three different monitors: the built-in one and the two connected to the docking station. If the lid is closed, only one of the monitors connected to the docking station is available.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]