我安装了 Nvidia 显卡，Ubuntu 直到昨天都运行正常。不幸的是，它现在卡在登录屏幕上。我切换到终端模式（Ctrl+Alt+F1）并使用以下命令删除了 Nvidia 驱动程序：
sudo apt-get purge nvidia-*
成功了！但是我想使用 Nvidia 驱动程序，因此成功登录后，我从 Ubuntu 中“软件和更新”下的“附加驱动程序”安装了 Nvidia 驱动程序。重启后，它再次卡在登录屏幕上。
.Xauthority以下是文件的权限信息：
ravi@lab:~$ ls -la .X*
-rw------- 1 ravi ravi 48 Feb 20 11:43 .Xauthority
-rw------- 1 ravi ravi 48 Feb 20 11:27 .Xauthority.bak
我无法找出问题的原因。以下是dmesg：
[ 1.342426] init: plymouth-upstart-bridge main process ended, respawning
[ 1.544607] Adding 16734204k swap on /dev/sda3. Priority:-1 extents:1 across:16734204k SSFS
[ 1.594473] systemd-udevd[359]: starting version 204
[ 1.596107] tsc: Refined TSC clocksource calibration: 3600.032 MHz
[ 1.620273] lp: driver loaded but no devices found
[ 1.631667] ppdev: user-space parallel port driver
[ 1.649728] wmi: Mapper loaded
[ 1.651556] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[ 1.681165] [drm] Initialized drm 1.1.0 20060810
[ 1.690956] type=1400 audit(1550630628.420:2): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/sbin/dhclient" pid=487 comm="apparmor_parser"
[ 1.690962] type=1400 audit(1550630628.420:3): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=487 comm="apparmor_parser"
[ 1.690965] type=1400 audit(1550630628.420:4): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/connman/scripts/dhclient-script" pid=487 comm="apparmor_parser"
[ 1.691995] type=1400 audit(1550630628.420:5): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/sbin/dhclient" pid=493 comm="apparmor_parser"
[ 1.691999] type=1400 audit(1550630628.420:6): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=493 comm="apparmor_parser"
[ 1.692002] type=1400 audit(1550630628.420:7): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/connman/scripts/dhclient-script" pid=493 comm="apparmor_parser"
[ 1.693989] snd_hda_intel 0000:00:1f.3: irq 182 for MSI/MSI-X
[ 1.768260] checking generic (d1000000 7f0000) vs hw (c0000000 10000000)
[ 1.768261] checking generic (d1000000 7f0000) vs hw (d0000000 2000000)
[ 1.768262] fb: conflicting fb hw usage nouveaufb vs EFI VGA - removing generic driver
[ 1.768280] Console: switching to colour dummy device 80x25
[ 1.768906] nouveau E[ DEVICE][0000:01:00.0] unknown chipset, 0x134000a1
[ 1.768910] nouveau E[ DRM] failed to create 0x80000080, -22
[ 1.769175] nouveau: probe of 0000:01:00.0 failed with error -22
[ 2.019597] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro
[ 2.229627] init: failsafe main process (750) killed by TERM signal
[ 2.415213] Bluetooth: Core ver 2.17
[ 2.415250] NET: Registered protocol family 31
[ 2.415251] Bluetooth: HCI device and connection manager initialized
[ 2.415255] Bluetooth: HCI socket layer initialized
[ 2.415257] Bluetooth: L2CAP socket layer initialized
[ 2.415259] Bluetooth: SCO socket layer initialized
[ 2.418438] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 2.418447] Bluetooth: BNEP filters: protocol multicast
[ 2.418451] Bluetooth: BNEP socket layer initialized
[ 2.425587] Bluetooth: RFCOMM TTY layer initialized
[ 2.425608] Bluetooth: RFCOMM socket layer initialized
[ 2.425634] Bluetooth: RFCOMM ver 1.11
[ 2.446701] type=1400 audit(1550630629.176:8): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/cups/backend/cups-pdf" pid=837 comm="apparmor_parser"
[ 2.446704] type=1400 audit(1550630629.176:9): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/sbin/cupsd" pid=837 comm="apparmor_parser"
[ 2.465787] init: cups main process (842) killed by HUP signal
[ 2.465817] init: cups main process ended, respawning
[ 2.497078] type=1400 audit(1550630629.224:10): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/sbin/cups-browsed" pid=916 comm="apparmor_parser"
[ 2.558491] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 2.588489] init: alsa-restore main process (1031) terminated with status 19
[ 2.598291] Switched to clocksource tsc
以下是sudo lshw -c video
ravi@lab:~$ sudo lshw -c video
[sudo] password for ravi:
*-display UNCLAIMED
description: VGA compatible controller
product: NVIDIA Corporation
vendor: NVIDIA Corporation
physical id: 0
bus info: pci@0000:01:00.0
version: a1
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress vga_controller cap_list
configuration: latency=0
resources: memory:de000000-deffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:e000(size=128) memory:df000000-df07ffff
PS：我知道类似的问题被问过很多次，但我无法找出这个问题的原因。我猜想一些 Nvidia 配置文件需要正确清理。
答案1
我也受到了这个错误/影响的影响。作为解决方法，我也首先切换到了 Nouveau 驱动程序。正如 ubuntuforums 上的链接主题（来自 user3409662）中已经提到的那样，上周已经更新了几个软件包，也是 shim-signed 的。有趣的是，这个软件包对我来说似乎不是必需的，因为几年前我使用 mokutil 禁用了我的系统（Ubuntu 14.04，Geforce GTX 750 Ti）的 SecureBoot（再次使用 VirtualBox 是必要的）。
所以我决定卸载 shimsigned（为此使用了 Synaptic），重新启动后没有看到任何负面影响。在终端中，我再次安装了之前使用的 Nvidia 驱动程序：
sudo apt-get install nvidia-410。没有出现任何错误，重新启动后图形登录再次正常工作，Nvidia 驱动程序已加载。测试了一些游戏（原生游戏和基于 Wine 的游戏）——一切正常。