我正在尝试使用 HDMI 电缆将第二台外接显示器连接到运行 Ubuntu 20.04 的 Dell XPS 15 笔记本电脑。
监视器在 Ubuntu 中根本没有显示。
到目前为止，我针对该问题尝试了以下操作：Ubuntu 16.04 Dell XPS 15 无法使用 HDMI 检测外接显示器
sudo add-apt-repository ppa:graphics-drivers/ppasudo apt updatesudo apt install nvidia-driver-455- 添加
nouveau.modeset=0到GRUB_CMDLINE_LINUX_DEFAULT/etc/default/grub sudo update-grub
仍然根本检测不到监视器（见xrandr下面的输出）。
如果我在安装 Nvidia 驱动程序后不进行设置nouveau.modeset=0，主（内部）显示器将在启动期间变黑，并且我只能使用虚拟终端。
我是否遗漏了这里的一个重要步骤？
$ lspci
00:00.0 Host bridge: Intel Corporation 8th Gen Core Processor Host Bridge/DRAM Registers (rev 07)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16) (rev 07)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 630 (Mobile)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 07)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Cannon Lake PCH Thermal Controller (rev 10)
00:14.0 USB controller: Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller (rev 10)
00:14.2 RAM memory: Intel Corporation Cannon Lake PCH Shared SRAM (rev 10)
00:15.0 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #0 (rev 10)
00:15.1 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #1 (rev 10)
00:16.0 Communication controller: Intel Corporation Cannon Lake PCH HECI Controller (rev 10)
00:17.0 SATA controller: Intel Corporation Cannon Lake Mobile PCH SATA AHCI Controller (rev 10)
00:1b.0 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #17 (rev f0)
00:1c.0 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #1 (rev f0)
00:1c.4 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #5 (rev f0)
00:1d.0 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #9 (rev f0)
00:1f.0 ISA bridge: Intel Corporation Device a30e (rev 10)
00:1f.3 Audio device: Intel Corporation Cannon Lake PCH cAVS (rev 10)
00:1f.4 SMBus: Intel Corporation Cannon Lake PCH SMBus Controller (rev 10)
00:1f.5 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH SPI Controller (rev 10)
01:00.0 3D controller: NVIDIA Corporation GP107M [GeForce GTX 1050 Ti Mobile] (rev a1)
3b:00.0 Network controller: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter (rev 32)
3c:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)
3d:00.0 Non-Volatile memory controller: Toshiba Corporation Device 0116
$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 2160, maximum 32767 x 32767
eDP-1-1 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
3840x2160 60.00*+ 59.98 59.97
3200x1800 59.96 59.94
2880x1620 59.96 59.97
2560x1600 59.99 59.97
2560x1440 59.99 59.99 59.96 59.95
2048x1536 60.00
1920x1440 60.00
1856x1392 60.01
1792x1344 60.01
2048x1152 59.99 59.98 59.90 59.91
1920x1200 59.88 59.95
1920x1080 60.01 59.97 59.96 59.93
1600x1200 60.00
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 59.99 59.94 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1440x810 60.00 59.97
1368x768 59.88 59.85
1360x768 59.80 59.96
1280x800 59.99 59.97 59.81 59.91
1152x864 60.00
1280x720 60.00 59.99 59.86 59.74
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
1024x576 59.95 59.96 59.90 59.82
960x600 59.93 60.00
960x540 59.96 59.99 59.63 59.82
800x600 60.00 60.32 56.25
840x525 60.01 59.88
864x486 59.92 59.57
800x512 60.17
700x525 59.98
800x450 59.95 59.82
640x512 60.02
720x450 59.89
700x450 59.96 59.88
640x480 60.00 59.94
720x405 59.51 58.99
684x384 59.88 59.85
680x384 59.80 59.96
640x400 59.88 59.98
576x432 60.06
640x360 59.86 59.83 59.84 59.32
512x384 60.00
512x288 60.00 59.92
480x270 59.63 59.82
400x300 60.32 56.34
432x243 59.92 59.57
320x240 60.05
360x202 59.51 59.13
320x180 59.84 59.32
DP-1-1 disconnected (normal left inverted right x axis y axis)
DP-1-2 disconnected (normal left inverted right x axis y axis)
DP-1-3 disconnected (normal left inverted right x axis y axis)
我最近从 Ubuntu 18 升级到了 20。在 18 上，我能够使用 XPS 的 USB-C 端口使用外接显示器。（我无法测试这在 20 上是否仍然有效，因为我这里没有显示器。）
xrandr由于根本检测不到 HDMI 输出，因此我无法手动设置输出：
$ xrandr --verbose --output eDP-1-1 --mode 3840x2160 --output HDMI-1 --left-of eDP-1 --mode auto
warning: output HDMI-1 not found; ignoring
crtc 0: 3840x2160 60.00 +0+0 "eDP-1-1"
该xserver-xorg-video-intel包已经安装。