[SOLVED] Annoying second monitor problem!

mabox · 2025-03-24 17:30:07

Hello all,
I use GNOME as my desktop, my system is always updated.
Some time ago an annoying problem crept in which I would now like to ask about.
It has become an absolute game of chance whether my freshly booted system recognizes my second monitor or not.
Most of the time it doesn't and I either have to switch the monitor on and off at least twice or even briefly disconnect it from the power supply once.
Even if the monitor has locked after a period of inactivity, this can happen and then my open windows are usually no longer in the same place and I have to rearrange them.
Actually, this has always worked, I would like to rule out that the monitor has a defect. A windows is also connected on the second port, unfortunately I need windows because of work :-( and everything continues to work there too.

Unfortunately, I have no idea what I can do at the moment. Does anyone have any idea what I need to check? Can someone analyze logs for me to see if there is anything? What logs and information do you need from me?

Many greetings
mabox

Last edited by mabox (2025-03-31 21:45:07)

seth · 2025-03-24 21:19:58

Gnome on X11 or wayland or doens't matter?
Is it a hybrid system (two GPUs)?

Please post your complete system journal for the boot:

sudo journalctl -b | curl -F 'file=@-' 0x0.st

and in case this (ideally, also) happens on X11, your Xorg log, https://wiki.archlinux.org/title/Xorg#General

Do you boot straight into a gnome session or do you use a DM?
Which? Is it affected as well?

mabox · 2025-03-25 05:30:07

Hi,
ok here is my output: https://0x0.st/8jWS.txt
I am using wayland, I am not booting in X11 and no hyprid system I think:

[root@tux ~]# lscpu
Architektur:                       x86_64
  CPU Operationsmodus:             32-bit, 64-bit
  Adressgrößen:                    48 bits physical, 48 bits virtual
  Byte-Reihenfolge:                Little Endian
CPU(s):                            16
  Liste der Online-CPU(s):         0-15
Anbieterkennung:                   AuthenticAMD
  Modellname:                      AMD Ryzen 7 5700U with Radeon Graphics
    Prozessorfamilie:              23
    Modell:                        104
    Thread(s) pro Kern:            2
    Kern(e) pro Sockel:            8
    Sockel:                        1
    Stepping:                      1
    Übertaktung:                   aktiviert
    Skalierung der CPU(s):         30%
    Maximale Taktfrequenz der CPU: 4372,0000
    Minimale Taktfrequenz der CPU: 400,0000
    BogoMIPS:                      3593,42
    Markierungen:                  fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmx
                                   ext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc cpuid extd_apicid aperfmperf rapl p
                                   ni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm ext
                                   apic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext p
                                   erfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 cqm rdt
                                   _a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local
                                    clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid dec
                                   odeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip rdpid overflow_recov succor smca
Virtualisierungsfunktionen:        
  Virtualisierung:                 AMD-V
Caches (Gesamtsumme):              
  L1d:                             256 KiB (8 Instanzen)
  L1i:                             256 KiB (8 Instanzen)
  L2:                              4 MiB (8 Instanzen)
  L3:                              8 MiB (2 Instanzen)
NUMA:                              
  NUMA-Knoten:                     1
  NUMA-Knoten0 CPU(s):             0-15
Schwachstellen:                    
  Gather data sampling:            Not affected
  Itlb multihit:                   Not affected
  L1tf:                            Not affected
  Mds:                             Not affected
  Meltdown:                        Not affected
  Mmio stale data:                 Not affected
  Reg file data sampling:          Not affected
  Retbleed:                        Mitigation; untrained return thunk; SMT enabled with STIBP protection
  Spec rstack overflow:            Mitigation; Safe RET
  Spec store bypass:               Mitigation; Speculative Store Bypass disabled via prctl
  Spectre v1:                      Mitigation; usercopy/swapgs barriers and __user pointer sanitization
  Spectre v2:                      Mitigation; Retpolines; IBPB conditional; STIBP always-on; RSB filling; PBRSB-eIBRS Not affected; BHI Not affected
  Srbds:                           Not affected
  Tsx async abort:                 Not affected

I am booting in display manager GDM and then login to GNOME.

EDIT:
Ok I have booted twice now and logged on over gdm with Xorg and the problem did not occur. Then I booted twice and logged in with Wayland and the problem was there again, so Wayland problem?

Last edited by mabox (2025-03-25 05:41:01)

seth · 2025-03-25 08:01:57

Is GDM affected (as well)?
Gnome manages the outputs in some xml, https://wiki.archlinux.org/title/GDM#Se … r_settings

Mär 25 06:31:02 tux kernel: [drm] DM_MST: DP12, 4-lane link detected
Mär 25 06:31:07 tux kernel: amdgpu 0000:05:00.0: [drm] *ERROR* Sending link address failed with -5

Are you daisy-chaining the outputs?

No idea whether this is relevant, but maybe get rid of the bogus session data

Mär 25 06:31:09 tux gnome-shell[909]: Failed to parse saved session file: Datei »/var/lib/gdm/.config/mutter/sessions/10865aea12e525d3b1174288066862334600000008970000.ms« konnte nicht geöffnet werden: Datei oder Verzeichnis nicht gefunden

so Wayland problem?

Might also just be the gnome configuration (the wiki points out that they're incompatible between x11 and wayland and x11 will by default just activate all present outputs) or a race condition (amdgpu loads early but maybe the output is late) - does it help to get some coffee before logging in?

tekstryder · 2025-03-25 14:41:23

seth wrote:

No idea whether this is relevant, but maybe get rid of the bogus session data

There is nothing to get rid of.

This is essentially another artifact of the first gnome/mutter session spawned by GDM before the "real" session is launched at login.

It's also likely a WONTFIX as it is fully harmless noise.

See:
• https://gitlab.gnome.org/GNOME/mutter/-/issues/2891

mabox · 2025-03-25 15:18:12

seth wrote:

Is GDM affected (as well)?
Gnome manages the outputs in some xml, https://wiki.archlinux.org/title/GDM#Se … r_settings

I don't see a problem in gdm, but it always starts “only” on the monitor on the laptop. Then I log in via x11 or wayland and then the image actually appears on both screens, notebook and second monitor.

seth wrote:

Are you daisy-chaining the outputs?

I don't know, I think not, just plugged in the monitor in the notebook port.

So it has always worked with X11, but one time it was also when the monitor locked itself that the second monitor was not recognized after unlocking. I then had to switch it off and on again briefly.
I have now rebooted and waited a few minutes before logging in via gdm, then it also worked via wayland. I think I'll have to test it again for a while. I'll keep testing between X11 and wayland and get back to you.

Last edited by mabox (2025-03-25 15:19:51)

seth · 2025-03-25 16:10:51

I have now rebooted and waited a few minutes before logging in via gdm, then it also worked via wayland.

If you don't wait, face a single output on login, then get some coffee (let's face it: I have a caffeine problem…) and the check the monitor configuration in gnome: is the output there and can you activate it?

max kaspar · 2025-03-25 16:32:00

Also check the cable. I had a similar problem with second monitor randomly working, and in the end it was the cable. Maybe the cable is not completely defective, but the the wires transfer signals only in some positions (twisted wires and loose contact).

mabox · 2025-03-26 16:15:31

seth wrote:

If you don't wait, face a single output on login, then get some coffee (let's face it: I have a caffeine problem…) and the check the monitor configuration in gnome: is the output there and can you activate it?

I don't think I quite understand, which output is meant?

max_kaspar wrote:

Also check the cable. I had a similar problem with second monitor randomly working, and in the end it was the cable. Maybe the cable is not completely defective, but the the wires transfer signals only in some positions (twisted wires and loose contact).

Good point, I will also check this...

seth · 2025-03-26 16:26:22

output = "monitor"

mabox · 2025-03-31 15:58:50

It's crazy, it seems that wiggling the cable or the plug on the usb-c port that the monitor is connected to has helped. It flickered briefly but it's been as it should be for days now.

seth · 2025-03-31 20:08:07

Rule #1: it's always the cable.

In case this remains true, please remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

mabox · 2025-03-31 21:43:44

Thank you for your help!

Arch Linux

#1 2025-03-24 17:30:07

[SOLVED] Annoying second monitor problem!

#2 2025-03-24 21:19:58

Re: [SOLVED] Annoying second monitor problem!

#3 2025-03-25 05:30:07

Re: [SOLVED] Annoying second monitor problem!

#4 2025-03-25 08:01:57

Re: [SOLVED] Annoying second monitor problem!

#5 2025-03-25 14:41:23

Re: [SOLVED] Annoying second monitor problem!

#6 2025-03-25 15:18:12

Re: [SOLVED] Annoying second monitor problem!

#7 2025-03-25 16:10:51

Re: [SOLVED] Annoying second monitor problem!

#8 2025-03-25 16:32:00

Re: [SOLVED] Annoying second monitor problem!

#9 2025-03-26 16:15:31

Re: [SOLVED] Annoying second monitor problem!

#10 2025-03-26 16:26:22

Re: [SOLVED] Annoying second monitor problem!

#11 2025-03-31 15:58:50

Re: [SOLVED] Annoying second monitor problem!

#12 2025-03-31 20:08:07

Re: [SOLVED] Annoying second monitor problem!

#13 2025-03-31 21:43:44

Re: [SOLVED] Annoying second monitor problem!

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