I have 3 Samsung Viewfinity S6 monitors in my setup, and sometimes when waking the computer from the state with displays off, one of the monitors will wake up then immediately show “No Signal” after waking.
It happens randomly and happens on my center or right monitor when it happens.
System Specs:
AMD Ryzen 7 5800X
G.Skill DDR4-3200 16GBx2
ASUS ROG B550-A
EVGA RTX 3070TI FTW3
Samsung 980 Pro 2TB SSD
Seasonic Focus GX-850
Linux Mint 21.3 with Nvidia Driver 535
My left monitor is connected with a 3m Lindy Slim Line Displayport Cable
My Center and right monitors are connected with 1.8m Lindy Anthra Displayport Cables.
I will post an update with a video when I catch it on camera
Mine is the same-ish over on Fedora 40.
It does not consistently fail the same way:
Sometimes the session gets logged out
Sometimes the session shuts down.
I have a L1T KVM and while that complicates things, I do not know if it is part of the problem or if my particular setup is just broken or maybe Linux isnt ready for primetime. I think I also did some changes in the BIOS involving power states (S1, S2, S3, S4 and S5 states) and I do not know what should be the correct settings for it.
I have the same thing that happens with:
RTX 4080Ti - Windows 11 Pro - 4 monitors
Quadro M2000 & GTX 1650 - Windows 11 Pro - 6 monitors
RX7600xt - Fedora 40 and Debian 12 - 1 TV
Quadro P1000 - Windows 10 Pro - 4 monitors
I do not have these problems with:
WX4100 - Windows 11 Pro - 4 monitors
WX4100 - Debian 12 - 4 monitors
RX6400 - Fedora 40 - 1 TV
These are all different machines with different monitors I use daily.
Low power states are disabled for all the machines which helped.
Unfortunately, Fedora is increasingly aggressive with power managements and causing no end of problems.
I do not have time to fully diag or replug in monitors that refuse to negotiate so I’ve resorted to leaving them on all the time or in the case of the TV that has issues, ran the video through a surround sound receiver that keeps the connection alive when off.
My understanding is the GPU enters a low power state with monitors disconnected and a race condition when they are all turned on simultaneously. No amount of monitor power cycles resolves the issue, have to physically disconnect then reconnect.