[radeon] Failure to pass system check and present login screen

[Kent Lion]

I'm reporting this against xorg, because of where the problem occurs, as indicated below, I can't tell if the problem is with xorg, lightdm or light-locker. The system is a Dell Optiplex 745 single-booting to Xubuntu 20.04 up-to-date as of today.

I replaced one of 2 monitors, the one rotated to portrait orientation, with a higher resolution monitor. Started the system, logged in as another user and changed the desktop background however, when I then logged out and restarted the system, it behaved normally until it displayed the usual
/dev/sda1: clean, xxxxx/xxxxx files, xxxx/xxxxx blocks
on both monitors. The prompt remained for a few seconds, slowly blinked off and on 6 times, and then remained with no further activity. The system works fine if I boot from a Xubuntu 18.04 DVD (I didn't have a 20.04 DVD, and this is the only machine with a burner). On another machine, I determined that the system was booting, because the machine was visible on the network, and its shared folders were accessible.

I could get to a login prompt and log on using Alt+F1 to F6. Alt-F7 returned me to the file system check prompt. I was able to start xorg after logging on with startx, and changing all settings for the new monitor, everything worked normally until logging out, which of course returned me to the command line where I had given the command startx.

If I log out requesting a restart, the system reboots, but still stops at the same place every time. That behavior hadn't changed the next day. I can use the machine, but only by selecting a terminal, logging as myself or the other user and giving the startx command. I have been unable to find anything on the Internet that corrects the problem. Since the problem first started, two crashes have occurred and I allowed them to be reported; however, they were light-locker crashes. I reinstalled lightdm and light-locker, but that made no difference. I installed gdm3, which works fine, but switching back to lightdm with:
sudo dpkg-reconfigure gdm3
sudo dpkg --configure lightdm
resulted in:
dpkg: error processing package lightdm (--configure):
 package lightdm is already installed and configured
Errors were encountered while processing:
 lightdm

So I can't really be sure if the problem is with xorg, lightdm or light-locker, but since there are no error messages and everything else works fine, it's clearly a bug, if a strange one. I do not relish the idea of having to reinstall Xubuntu; so for the time being, I'll use gdm3, though I prefer lightdm's ability to properly display backdrops and use the two monitors properly extended (with gdm3, the mouse moves down the left portrait monitor before moving onto the right monitor where gdm3 sees fit to put the logon dialog). The next thing I'll try is autoremoving lightdm rebooting a few times and then reinstalling it...

Because of the absence of error messages and information even suggesting why X isn't starting, I have no idea what other information about my system might be useful to you, but if you need something additional, I'll try to provide it.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-65.73-generic 5.4.78
Uname: Linux 5.4.0-65-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: XFCE
Date: Fri Jan 29 22:12:37 2021
DistUpgraded: 2020-10-20 06:56:14,405 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 6.1.16, 5.4.0-62-generic, x86_64: installed
 virtualbox, 6.1.16, 5.4.0-65-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] RV620 LE [Radeon HD 3450] [1002:95c5] (prog-if 00 [VGA controller])
   Subsystem: Dell OptiPlex 980 [1028:0342]
InstallationDate: Installed on 2019-11-29 (427 days ago)
InstallationMedia: Xubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
MachineType: Dell Inc. OptiPlex 780
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-65-generic root=UUID=68c4f426-dc84-48e8-be0f-cd1a5acfb729 ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to focal on 2020-10-20 (101 days ago)
dmi.bios.date: 08/06/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A15
dmi.board.name: 0C27VV
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 6
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA15:bd08/06/2013:svnDellInc.:pnOptiPlex780:pvr:rvnDellInc.:rn0C27VV:rvrA00:cvnDellInc.:ct6:cvr:
dmi.product.name: OptiPlex 780
dmi.sys.vendor: Dell Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx 20.2.6-0ubuntu0.20.04.1
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

It would be useful to find out why gdm3 works for you but lightdm does not. It might be because gdm3 defaults to Wayland not Xorg, or it might be a difference in the greeter/login screen itself. To find out, please try editing /etc/gdm3/custom.conf and change:

  #WaylandEnable=false

to

  WaylandEnable=false

then reboot.

Does gdm3 still work now it's using Xorg?

[Launchpad Janitor (janitor)]

[Expired for unity-greeter (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for lightdm (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for xorg-server (Ubuntu) because there has been no activity for 60 days.]