[Solved] Ubuntu 22.04 displayport cutting in and out

[raphael75]

I have Ubuntu 22.04 and an NVIDIA Corporation GA102 GeForce RTX 3080 video card. The video card has 3 Displayport outputs and 1 HDMI. I have an ASUS VE278 monitor that has the HDMI plugged in and it works fine. The HDMI is plugged in with an HDMI cable going from the computer to a KVM, and another HDMI cable from the KVM to the ASUS VE278.

I also have an ASUS VE276 that has the Displayport plugged in. This has a Displayport cable going straight from the computer to the VE276.

When the computer is booting, Both screens show the POST, the Ubuntu loading logo, the login screens, etc.

However, when it finally loads into KDE, the Displayport monitor goes black and I get "DisplayPort No Signal" on the screen.

I am using the Nvidia video driver:

lspci | grep VGA
01:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3080 12GB] (rev a1)

monitors currently found:

xrandr --listmonitors
Monitors: 1
 0: +*HDMI-0 1920/598x1080/336+0+0  HDMI-0

More info:

lspci -k | grep -EA3 'VGA|3D|Display'
01:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3080 12GB] (rev a1)
        Subsystem: Micro-Star International Co., Ltd. [MSI] Device 389b
        Kernel driver in use: nvidia
        Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia

Why would it see the DisplayPort monitor as everything is booting, and then not be able to find it when KDE finally loads?

 

[Deleted member 108694]

Why would it see the DisplayPort monitor as everything is booting, and then not be able to find it when KDE finally loads?

Most likely the Nvidia drivers have not loaded until it gets to the login screen - you can try just running the Nouveau drivers and see if both monitors start working - you can change it in Software & Updates click on Additional Drivers and select Nouveau click apply reboot and see what happens

 

[KGIII]

I was wondering, when I first saw this, if you'd actually also configured it in your display options.

I figured that was way too obvious and that you must have done so. So, I didn't ask. @Lord Boltar's comment reminded me the thread existed and I see it had little activity, so I might as well throw it out there. Though, I'd like to think folks would check that first before asking.

 

[raphael75]

Thanks for your replies! If I go to display settings the other monitor doesn't show up:

It looks like it does see the monitor here (DP-4):

$ xrandr --verbose
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
HDMI-0 connected primary 1920x1080+0+0 (0x1bd) normal (normal left inverted right x axis y axis) 598mm x 336mm
        Identifier: 0x1bc
        Timestamp:  1038535
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:   
        CRTC:       0
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff000469f627d9d50000
                03190103803c22782aeed5a555489b26
                125054b7ef00714f81c0814081809500
                b300d1c00101023a801871382d40582c
                450056502100001e000000ff0046314c
                4d54463035343734350a000000fd0032
                55185c11000a202020202020000000fc
                00415355532056453237380a20200138
                020322714f0102031112130414050e0f
                1d1e1f10230907018301000065030c00
                10008c0ad08a20e02d10103e96000925
                21000018011d007251d01e206e285500
                09252100001e011d00bc52d01e20b828
                554009252100001e8c0ad09020403120
                0c405500092521000018000000000000
                00000000000000000000000000000073
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: TMDS
                supported: TMDS
        ConnectorType: HDMI
        ConnectorNumber: 3
        _ConnectorLocation: 3
        non-desktop: 0
                supported: 0, 1
  1920x1080 (0x1bd) 148.500MHz +HSync +VSync *current +preferred
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x1be) 148.350MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1920x1080 (0x1bf) 148.500MHz +HSync +VSync
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz
  1680x1050 (0x1c0) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1440x900 (0x1c1) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934           clock  59.89Hz
  1440x576 (0x1c2) 54.000MHz -HSync +VSync
        h: width  1440 start 1464 end 1592 total 1728 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  1440x480 (0x1c3) 54.000MHz -HSync -VSync
        h: width  1440 start 1472 end 1596 total 1716 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  1280x1024 (0x1c4) 135.000MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock  79.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  75.02Hz
  1280x1024 (0x1c5) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1280x960 (0x1c6) 108.000MHz +HSync +VSync
        h: width  1280 start 1376 end 1488 total 1800 skew    0 clock  60.00KHz
        v: height  960 start  961 end  964 total 1000           clock  60.00Hz
  1280x720 (0x1c7) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x1c8) 74.180MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1280x720 (0x1c9) 74.250MHz +HSync +VSync
        h: width  1280 start 1720 end 1760 total 1980 skew    0 clock  37.50KHz
        v: height  720 start  725 end  730 total  750           clock  50.00Hz
  1152x864 (0x1ca) 108.000MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock  67.50KHz
        v: height  864 start  865 end  868 total  900           clock  75.00Hz
  1024x768 (0x1cb) 78.750MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock  60.02KHz
        v: height  768 start  769 end  772 total  800           clock  75.03Hz
  1024x768 (0x1cc) 75.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock  56.48KHz
        v: height  768 start  771 end  777 total  806           clock  70.07Hz
  1024x768 (0x1cd) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  800x600 (0x1ce) 49.500MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock  46.88KHz
        v: height  600 start  601 end  604 total  625           clock  75.00Hz
  800x600 (0x1cf) 50.000MHz +HSync +VSync
        h: width   800 start  856 end  976 total 1040 skew    0 clock  48.08KHz
        v: height  600 start  637 end  643 total  666           clock  72.19Hz
  800x600 (0x1d0) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x1d1) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  720x576 (0x1d2) 27.000MHz -HSync -VSync
        h: width   720 start  732 end  796 total  864 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  720x480 (0x1d3) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  640x480 (0x1d4) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock  37.50KHz
        v: height  480 start  481 end  484 total  500           clock  75.00Hz
  640x480 (0x1d5) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
  640x480 (0x1d6) 25.170MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.46KHz
        v: height  480 start  490 end  492 total  525           clock  59.93Hz
DP-0 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x1d7
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000help forum
                   filter:
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: DisplayPort
                supported: DisplayPort
        ConnectorType: DisplayPort
        ConnectorNumber: 2
        _ConnectorLocation: 2
        non-desktop: 0
                supported: 0, 1
DP-1 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x1d8
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: TMDS
                supported: TMDS
        ConnectorType: DisplayPort
        ConnectorNumber: 2
        _ConnectorLocation: 2
        non-desktop: 0
                supported: 0, 1
DP-2 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x1d9
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: DisplayPort
                supported: DisplayPort
        ConnectorType: DisplayPort
        ConnectorNumber: 1
        _ConnectorLocation: 1
        non-desktop: 0
                supported: 0, 1
DP-3 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x1da
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: TMDS
                supported: TMDS
        ConnectorType: DisplayPort
        ConnectorNumber: 1
        _ConnectorLocation: 1
        non-desktop: 0
                supported: 0, 1
DP-4 connected (normal left inverted right x axis y axis)
        Identifier: 0x1db
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff000469f427b5610000
                0d150104a53c22782aeed5a555489b26
                125054bfef00714f81c0814081809500
                950fb300d1c0023a801871382d40582c
                450056502100001e000000ff0042344c
                4d54463032353031330a000000fd0032
                55185c11041150d2f858f000000000fc
                00415355532056453237360a20200160
                020322714f0102031112130414051f10
                0e0f1d1e230907018301000065030c00
                10008c0ad08a20e02d10103e96005650
                21000018011d007251d01e206e285500
                56502100001e011d00bc52d01e20b828
                554056502100001e8c0ad09020403120
                0c405500565021000018000000000000
                00000000000000000000000000000093
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: DisplayPort
                supported: DisplayPort
        ConnectorType: DisplayPort
        ConnectorNumber: 0
        _ConnectorLocation: 0
        non-desktop: 0
                supported: 0, 1
  1920x1080 (0x1bd) 148.500MHz +HSync +VSync +preferred
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x1be) 148.350MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1920x1080 (0x1bf) 148.500MHz +HSync +VSync
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz
  1680x1050 (0x1c0) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1440x900 (0x1dc) 136.750MHz -HSync +VSync
        h: width  1440 start 1536 end 1688 total 1936 skew    0 clock  70.64KHz
        v: height  900 start  903 end  909 total  942           clock  74.98Hz
  1440x900 (0x1c1) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934         help forum  clock  59.89Hz
  1440x576 (0x1c2) 54.000MHz -HSync +VSync
        h: width  1440 start 1464 end 1592 total 1728 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  1440x480 (0x1c3) 54.000MHz -HSync -VSync
        h: width  1440 start 1472 end 1596 total 1716 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  1280x1024 (0x1c4) 135.000MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock  79.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  75.02Hz
  1280x1024 (0x1c5) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1280x960 (0x1c6) 108.000MHz +HSync +VSync
        h: width  1280 start 1376 end 1488 total 1800 skew    0 clock  60.00KHz
        v: height  960 start  961 end  964 total 1000           clock  60.00Hz
  1280x720 (0x1c7) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x1c8) 74.180MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1280x720 (0x1c9) 74.250MHz +HSync +VSync
        h: width  1280 start 1720 end 1760 total 1980 skew    0 clock  37.50KHz
        v: height  720 start  725 end  730 total  750           clock  50.00Hz
  1152x864 (0x1ca) 108.000MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock  67.50KHz
        v: height  864 start  865 end  868 total  900           clock  75.00Hz
  1024x768 (0x1cb) 78.750MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock  60.02KHz
        v: height  768 start  769 end  772 total  800           clock  75.03Hz
  1024x768 (0x1cc) 75.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock  56.48KHz
        v: height  768 start  771 end  777 total  806           clock  70.07Hz
  1024x768 (0x1cd) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  800x600 (0x1ce) 49.500MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock  46.88KHz
        v: height  600 start  601 end  604 total  625           clock  75.00Hz
  800x600 (0x1cf) 50.000MHz +HSync +VSync
        h: width   800 start  856 end  976 total 1040 skew    0 clock  48.08KHz
        v: height  600 start  637 end  643 total  666           clock  72.19Hz
  800x600 (0x1d0) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x1d1) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  720x576 (0x1d2) 27.000MHz -HSync -VSync
        h: width   720 start  732 end  796 total  864 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  720x480 (0x1d3) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  640x480 (0x1d4) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock  37.50KHz
        v: height  480 start  481 end  484 total  500           clock  75.00Hz
  640x480 (0x1dd) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  696 total  832 skew    0 clock  37.86KHz
        v: height  480 start  481 end  484 total  520           clock  72.81Hz
  640x480 (0x1d5) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
  640x480 (0x1d6) 25.170MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.46KHz
        v: height  480 start  490 end  492 total  525           clock  59.93Hz
DP-5 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x1de
        Timestamp:  1038535
        Subpixel:   unknown
        Clones:   
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0
                0 1
        CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
        BorderDimensions: 4
                supported: 4
        Border: 0 0 0 0
                range: (0, 65535)
        SignalFormat: TMDS
                supported: TMDS
        ConnectorType: DisplayPort
        ConnectorNumber: 0
        _ConnectorLocation: 0
        non-desktop: 0
                supported: 0, 1

But it doesn't show up in the list:

$ xrandr --listmonitors
Monitors: 1
 0: +*HDMI-0 1920/598x1080/336+0+0  HDMI-0

Does that indicate that I need to switch drivers, or is there something else going on?

 

[KGIII]

It doesn't show up in the drop-down menu starting with "Device" (in your image)?

 

[raphael75]

Oh man, I didn't notice that dropdown. It does show up there, and I activated it! Thank you SO much!

 

[KGIII]

No problem and glad it's sorted.

It turned out to be the simple stuff that was overlooked after all. Sorry about that. I could have resolved this on Monday for you. I just figured it was something deeper, so moved along.

And, don't feel bad/awkward for it being 'simple'. There's a lot to learn with Linux and it's VERY easy to overlook the small stuff. I've done so myself. I've even reinstalled only to later realize it was just a setting I overlooked.

I'll edit this to mark it solved.

 

[raphael75]

Thanks for your encouragement. I've used Debian and Ubuntu at work for several years, but it's been almost entirely command-line stuff. This is the first time I'm trying to use Ubuntu/KDE as a main desktop and like you said, there's a lot of little details to learn. Thanks again!