[ISSUE xubuntu 16.04 7870HD amdgpu-pro 17.40/17.50] Newly connected screen does not output signal until you configure it using a secondary monitor

Discussion created by hipunk on Jan 11, 2018
Latest reply on Jan 18, 2018 by colesdav




I am running xubuntu 16.04.3 and I encounter an issue/bug that is really annoying:

I have to switch my computer monitor between several computers. The setup is multiple computers with one monitor.

There is a switch that allows switching between computers. But the problem exists as well when unplugging/changing the cable.

The results are the same.


I switch from my desktop PC with AMD graphics to another machine and then back. Be it using the switch or by unplugging the other machine and plugging in the desktop with AMD graphics. When doing so, the AMD graphics card does not output a signal.

Not a black screen but no signal.


To avoid this problem I have to use a weird and ultimately annoying workaround: I have to plug my AMD graphics card into my PC monitor twice. One time using HDMI output OR (results are the same with DVI and HDMI) DVI output AND one time using analog VGA. When I reconnect the PC, the monitor switches over to VGA input. From there I configure it to using HDMI (or DVI) again.
To see where I configure, look here:


Two monitors are visible, but it's really just the same monitor plugged in twice. Into one graphics card.

This is the only way to recover from this problem in this config:


That is a lot of VRAM wasted for nothing.


I know that this bug only exists on Linux. I have used version amdgpu-pro 17.40 492261 for half a year. I just updated to 17.50 511655. The issue persists.

This bug does not appear on Mac OS X 10.10 - 10.13 on this computer (other versions are untested). This bug does not appear on Windows 7 or 8.1 on this computer (other versions are untested). This bug is Linux only. I do not know if other Linux distros or kernels have the same bug, I don't have enough resources to test this.


The specifications are as follows:

Logicboard: Gigabyte Z77X-UD3H.

Graphics accelerator: Sapphire AMD Radeon 7870HD 2GB oc edition.

Central Processing Unit: Intel Core i5 2500k.

Sufficient power supply.

Tested memory without errors.

Screen: Belinea 22". The issue happens with other screens as well.

Operating System: xubuntu 16.04.2 upgraded to 16.04.3.

Kernel: Linux 4.10.0-42-generic.


If you need more information, let me know. I can provide you with log files if needed.


Please fix this issue. It wastes everyones time and even managed to make me quite angry about AMD over the course of the last few months and is utterly frustrating, to say the least.

Other than that I am quite happy with AMDGPU/AMDGPU-PRO, I appreciate it over fglrx. Thanks for having created it.



Greetz from germany,