SOLVED - Distorted display on one of three monitors at every boot.

ChrisSaturn · 2024-08-22 05:44:26

I've been tinkering in Linux for the last 25 years or so, but I'm now trying to convert to it full time (outside of work). I'm still pretty new to Arch, so apologies in advance if I missed something obvious.

I've got three monitors connected to my Nvidia RTX 3070 video card. Two of them are 4k60, the other is 1080p60. When I first installed Arch from the command line, everything looked fine on all three monitors. The first time I got in the DE, the 1080p monitor displayed very distorted (before and after pictures here). After a bit of troubleshooting, I discovered I could change the color space on that specific monitor from RGB to YCbCr444 in the Nvidia X Server Settings and it would fix the issue. However, the image is still distorted on the login screen (with either lightdm or sddm), and continues to be distorted after every login until I open the Nvidia Settings panel. I don't even have to change anything in the settings, just opening it is enough to fix the problem.

I've exported the xorg configuration from the Nvidia X Server Settings, and that saved the layout and orientation of the monitors, but not the color space. Is there something I can edit to change the color space on just that one monitor at every boot? I'd like to leave the other two on RGB if possible.

Xorg.o.log

Thanks in advance for any help, and let me know if there's more information that I should have provided.

Last edited by ChrisSaturn (2024-09-06 11:48:14)

cryptearth · 2024-08-22 07:12:17

As you're able to change the color from RGB to YUV hints that this monitor is connected via a logical HDMI link (as in at least one end of the cable is HDMI). Have you tried other connection types like DVI or DisplayPort?
Have you tried just the 1080-screen on its own without the 4k-screens?
If the OSD of the 1080-screen has such an option try a factory reset - maybe it is set to a different profile than what the gpu starts up with, maybe it could be conflicting. If the reset of the monitor does not help: Try other profiles if the OSD provides options for it.
Sanity check: Do you have other devices or another gpu on hand you can test the 1080-screen with? Could be some hardware just not liking eachother rather than some software - although interesting seem to be abe to fix it.

ChrisSaturn · 2024-08-22 08:05:04

I tried to reset the monitor, but no change. It still gives the issue at reboot. The monitor has VGA, DVI, and HDMI connections, but the video card only has 3xDP and 1xHDMI, so it's plugged into the solo HDMI port. I might see if I can find an older video card to install to see if that changes anything.

I tried going with just the 1080p monitor on its own, and it still does the same as soon as I get to the login screen.

The monitor auto-detects whatever color space it should use in Windows (and also looks fine during the command line Arch install), but I'm trying to get away from needing to boot into Windows on this machine anymore.

Last edited by ChrisSaturn (2024-08-22 08:10:00)

seth · 2024-08-22 08:06:42

Remove the nvidia-settings generated config, you only need and want an augmneting drop-in, not that cruft.
/etc/X11/xorg.conf.d/20-nvidia.conf

 /etc/X11/xorg.conf.d/20-nvidia.conf
Section "Device"                                                                                                                
    Identifier "RTX3070"
    Driver  "nvidia"
    Option "ColorSpace" "DFP-0: YCbCr444"
EndSection

GPU and monitor should™ hash this out themselves, as cryptearth pointed out, there's possibly some adapter involved, but in any event enable https://wiki.archlinux.org/title/NVIDIA … de_setting - use the "nvidia_drm.modeset=1" kernel parameter (modprobe.conf won't do!) to get rid of the simpledrm device and expose the EDIDs to the drm subsystem - maybe that helps you out (otherwise you'll have a hard time controlling this if you ever want to run a wayland system)

needing to boot into Windows on this machine anymore.

3rd link below. Mandatory.
Disable it (it's NOT the BIOS setting!) and reboot windows and linux twice for voodo reasons.

ChrisSaturn · 2024-08-22 08:30:42

I tried all of those steps, but it was still doing the same thing. I tried adding that piece of code you specifed into the main xorg.conf, and now it's working great. Was there a step I was missing that prevented it from seeing the 20-nvidia.conf file I created?

Thank you for all the help, by the way! I'm very happy that it's working now, I'm just hoping to learn a little more about what I might have done wrong.

seth · 2024-08-22 08:34:28

Was there a step I was missing that prevented it from seeing the 20-nvidia.conf file I created?

Predominantly

the main xorg.conf

Remove that, re-add the drop-in and post an updated xorg log so we can see what gets picked up resp. maybe why not.

ChrisSaturn · 2024-08-22 10:19:43

Here's the updated xorg log. Is there something I should have added to xorg.conf to get it to see the 20-nvidia.conf file?

cryptearth · 2024-08-22 10:21:48

ChrisSaturn wrote:

Is there something I should have added to xorg.conf to get it to see the 20-nvidia.conf file?

if I'm not mistaken you have to remove xorg.conf as it overrides the drop-in files

ChrisSaturn · 2024-08-22 10:38:31

Oh, I didn't realize I could remove it outright. Alright, after removing it, the monitor seems to work great! Thanks again for all of the help!

seth · 2024-08-22 14:11:30

The static server configuration will completely bypass generic drop-ins.
You're for this and flexibility reasons highly discouraged from writing (let alone autogenerating) one.
The canonical approach is to rely on the servers autodetection at start and only nudge it with minimal drop ins.

Please always 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.

Arch Linux

#1 2024-08-22 05:44:26

SOLVED - Distorted display on one of three monitors at every boot.

#2 2024-08-22 07:12:17

Re: SOLVED - Distorted display on one of three monitors at every boot.

#3 2024-08-22 08:05:04

Re: SOLVED - Distorted display on one of three monitors at every boot.

#4 2024-08-22 08:06:42

Re: SOLVED - Distorted display on one of three monitors at every boot.

#5 2024-08-22 08:30:42

Re: SOLVED - Distorted display on one of three monitors at every boot.

#6 2024-08-22 08:34:28

Re: SOLVED - Distorted display on one of three monitors at every boot.

#7 2024-08-22 10:19:43

Re: SOLVED - Distorted display on one of three monitors at every boot.

#8 2024-08-22 10:21:48

Re: SOLVED - Distorted display on one of three monitors at every boot.

#9 2024-08-22 10:38:31

Re: SOLVED - Distorted display on one of three monitors at every boot.

#10 2024-08-22 14:11:30

Re: SOLVED - Distorted display on one of three monitors at every boot.

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