I have Nvidia graphics card installed and the Ubuntu used to work without any issue till yesterday. Unfortunately, it is now stuck at the login screen. I switched to terminal mode (Ctrl+Alt+F1) and removed Nvidia drivers using the following command:
sudo apt-get purge nvidia-*
It works! However, I want to use Nvidia drivers so after logging in successfully, I installed Nvidia drives from "additional drivers" under "software and updates" in Ubuntu. After rebooting, it again stuck at login screen.
Below is the permission info. for .Xauthority file:
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
I am not able to figure out the cause of the problem. Below is the content of 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
Below is the content of 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: I know the similar type of questions is asked many times but I am not able to figure out the cause of this problem. I guess that some Nvidia configuration files need to be cleaned properly.
I also was affected by this bug/effect. As workaround I also switched to the Nouveau driver first. As in the linked topic at ubuntuforums (from user3409662) was mentioned already, several packages have been updated last week, also shim-signed. Interestingly this package seems not to be necessary for me, because I disabled SecureBoot for my system (Ubuntu 14.04, Geforce GTX 750 Ti) by using mokutil some years ago (necessary to use VirtualBox again).
So I decided to uninstall shimsigned (used Synaptic for this), rebooted and saw no negative effects. In the terminal I installed my previously used Nvidia driver again:
sudo apt-get install nvidia-410. No errors appeared and after rebooting the graphical login was working again, Nvidia driver loaded. Tested some games (native and Wine based ones) – everything worked.