我有 Ubuntu 22.04 和 NVIDIA Corporation GA102 GeForce RTX 3080 显卡。该显卡有 3 个 Displayport 输出和 1 个 HDMI。我有一台华硕 VE278 显示器，已插入 HDMI，工作正常。HDMI 已插入，一根 HDMI 电缆从计算机连接到 KVM，另一根 HDMI 电缆从 KVM 连接到华硕 VE278。
我还有一台已插入 Displayport 的 ASUS VE276。它有一条 Displayport 电缆，可直接从计算机连接到 VE276。
当计算机启动时，两个屏幕都会显示 POST、Ubuntu 加载徽标、登录屏幕等。
然而，当它最终加载到 KDE 时，Displayport 显示器变黑并且屏幕上显示“DisplayPort 无信号”。
我正在使用 Nvidia 视频驱动程序：
lspci | grep VGA
01:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3080 12GB] (rev a1)
监视器当前发现：
xrandr --listmonitors
Monitors: 1
0: +*HDMI-0 1920/598x1080/336+0+0 HDMI-0
更多信息：
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
为什么在一切启动时它会看到 DisplayPort 显示器，而在 KDE 最终加载时却找不到它？
答案1
我注意到当我运行此命令（DP-4）时监视器确实出现了：
$ 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
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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
原来，显示设置中有一个下拉菜单，我必须在那里启用它。它就在屏幕下方，标有“设备”。我刚刚选择了另一台显示器并选中了启用框：
