Arch Linux

merc68k

Member

Registered: 2011-08-07

Posts: 31

[SOLVED] amdgpu RX5700xt monitors changing ID after powersave/unplug

Hi all,

I've upgraded from Intel integrated graphics to an rx5700xt.  Since doing so I've been having problems with my dual displays over displayport.

What's happening is that after leaving the machine for a while, so that the displays might go into powersave mode, I will sometimes come back to the machine and have only one display functional.  The other will be blank but if I power it off or unplug and replug the DP cable, the image will be restored.   Sometimes this happens to both displays.
When this does happen it usually confuses my desktop environment (XFCE and also KDE plasma) and I have to reconfigure the display in each.

It feels like it could be a similar issue to:  this, but the symptoms are not exactly the same.

I did try adding "amdgpu.runpm=0" but this doesn't seem to have helped.

Today I did some testing and noticed that on a fresh boot, the two displays are connected to DisplayPort-3 and DisplayPort-5 (as per the output of xrandr) but if I unplug the one on DisplayPort-3 and re-connect it (to the same physical port on the card), it will then be on DisplayPort-4.  The same goes for the other display which will be on DisplayPort-6.  After this initial change, any subsequent disconnecting or powering off of the displays does not change which port the displays are associated with.  I suspect this is what's causing my desktop environments to get mixed up if they are looking at the connected displays/ports to arrange things.

I have no other problems while I am working at the machine all day long; it really seems related to the machine and/or displays being idle.

Any ideas what might be going on here?

Here are the versions of the kernel and amdgpu:

$ pacman -Q | grep -E '^linux 6|amd'
linux 6.1.11.arch1-1
xf86-video-amdgpu 22.0.0-1

And the Radeon card from lspci:

$ lspci | grep VGA
03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] (rev c1)

Last edited by merc68k (2023-02-23 16:36:21)

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 14,893

Re: [SOLVED] amdgpu RX5700xt monitors changing ID after powersave/unplug

Yup, DP assignments change a lot* .

https://wiki.archlinux.org/title/Multihead should give you an idea what can be done .

* Not sure why but it might be related to the multi stream transport support added in DP 1.2 (sometimes referred to as daisy-chaining monitors) .

---

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Try clean chroot manager by graysky

merc68k

Member

Registered: 2011-08-07

Posts: 31

Re: [SOLVED] amdgpu RX5700xt monitors changing ID after powersave/unplug

@Lone_Wolf, thanks, I had read through the multi-head page already and tried a few things but I'll give it another look.  For now I've turned off power management on the displays which has helped.

It seems like a bug that the assignments would change like that.  As you mentioned daisy-chaining, that's actually how I had my screens connected when I was using Intel video, mainly because my motherboard only had a single DP output.  I switched to running the cables directly to see if it would improve this problem, and it might be less frequent now but still happens.

merc68k

Member

Registered: 2011-08-07

Posts: 31

Re: [SOLVED] amdgpu RX5700xt monitors changing ID after powersave/unplug

I think (hope) I've fixed the issue by turning off support for DP 1.2 on my two monitors.  I haven't had any issues since making that change and the port assignments are staying the same even after unplugging and re-plugging the monitors.  Maybe it's a bug in the implementation on the monitors themselves.