Arch Linux

stormj99

Member

Registered: 2017-04-20

Posts: 1

Displayport to HDMI not working?

First I'd like to say that while this is my first post, I have been using Arch Linux for a number of years.  Anyway, on to my problem.  For the past year or so (maybe two?) I have been using a triple head setup with three identical monitors.  For display output, one of them is running from a DVI-to-HDMI cable, the other HDMI, and the last is running on a displayport-to-HDMI converter (active).  Since a few months ago (I believe there was a kernel update) I have been unable to receive any output from the displayport adapter.  This is both in the terminal and in X.  However, it seems to display just fine (sort of) if I set the resolution to interlaced mode on that monitor.  I've tried this with multiple video cards (an R9 Fury with AMDGPU and an HD6870 with the Radeon driver), but to no avail.  Suggestions?

Edit:  I forgot to add that all three monitors work fine under windows.

Last edited by stormj99 (2017-04-20 04:14:43)

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: Displayport to HDMI not working?

I would say that's an EDID problem (which could be not probably translated). What's the output of xrandr --verbose? Can you try to set the correct resolution with xrandr. What do you see in Xorg.0.log? You can try also to see the EDID of the monitor. It is somewhere in /sys (for example mine is ./devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card0/card0-DVI-D-1/edid, but you can easily find it with the find command). You need edid-decode from the AUR to decode it in human readable format.