HP Elitebook 840 G3 Monitor Issue

Question

I have a Elitebook 840 G3 with two external monitors exposed via a docking port. If I have one monitor turned on, everything works great, even removing the PC from the docking port and reconnecting.

But I run into issues when attempting to use more then one monitor... beit the built in screen and one external, two externals, or all three.

It seems to work some of the time, other times, the system locks up hard. (Pressing numlock doesn't even turn the light on or off).

Anyway advice on how to debug the issue?

Answer 1

I had the same problem.

Upgrading the kernel from 4.4.0 to 4.4.14 worked for me. You can check your kernel release by typing uname -r in the terminal.

Here's a quick tutorial to upgrading the kernel

You can skip straight to the 64bit section.

You can try to upgrade your kernel to 4.4.14:

cd /tmp
wget kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.14-xenial/linux-headers-4.4.14-040414-generic_4.4.14-040414.201606241434_amd64.deb
wget kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.14-xenial/linux-headers-4.4.14-040414_4.4.14-040414.201606241434_all.deb
wget kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.14-xenial/linux-image-4.4.14-040414-generic_4.4.14-040414.201606241434_amd64.deb
sudo dpkg -i linux-headers-4.4.14*.deb linux-image-4.4.14*.deb

If you encounter problems, you can uninstall with:

sudo apt-get remove linux-headers-4.4.14* linux-image-4.4.14*

Answer 2

I am using HP EliteBook 840 G3/8079 on ubuntu 16.04. I have one hdmi and one vga external monitor. With stock kernel I get frequent lock ups, especially when using the dock. With 4.6-rc7 from kernel.org I still get lock ups with the dock especially when shutting down. Without the dock and by disabling displays power management the system is more stable / usable but still exhibits not so frequent lock ups.

From searching the internet I have the impression that skylake graphics support on linux is a complete mess. There are numerous reports of various problems especially with ultrabooks / docks / display port support.

My suggestion to those who wish to use linux is to avoid skylake.

Answer 3

Similar issues here with the exception that I also had many freeze problems not only when docking/undocking with multiple monitors attached, but only connecting/disconnecting VGA or DisplayPort cables.

In my case upgrading to kernel 4.6 mainline did the trick (using Ubuntu 16.04/64).

Answer 4

Upgrading kernel to 4.6.7 solves the problem of freeze while docking/undocking and also external display detection while plugging it on VGA connector.