Gfilui

When my Xubuntu 18.04 laptop resumes from suspend, systemd-logind automatically logs out of the current session if the laptop has stayed suspended for more than a couple of hours. If the interval between suspend and resume is short, it doesn't log out. I still haven't discovered how long this interval has to be in order to cause the logout.

I enabled debug on the systemd-logind.service, creating file /etc/systemd/system/systemd-logind.service.d/10-debug.conf:

[Service]
Environment=SYSTEMD_LOG_LEVEL=debug

which causes systemd-logind to log all D-Bus messages it handles, but couldn't spot anything that might have caused the logout.

I scanned all systemd journal messages (journalctl) before systemd-logind starts killing the current session, investigated all that looked suspicious but couldn't find anything that might influence an automatic logout. Here are some of the messages that striked me as suspicious (they are not sequential, but pulled from different occasions):

upowerd[1600]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4/1-1.4:1.0
polkitd(authority=local)[840]: Unregistered Authentication Agent for unix-session:c2 (system bus name :1.46, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
wpa_supplicant[811]: dbus: fill_dict_with_properties dbus_interface=fi.w1.wpa_supplicant1.Interface dbus_property=Stations getter failed
wpa_supplicant[811]: dbus: wpa_dbus_get_object_properties: failed to get object properties: (none) none
at-spi-bus-launcher[7031]: XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":0.0"
at-spi-bus-launcher[7031]: after 30333 requests (30333 known processed) with 0 events remaining.
systemd-logind[779]: Inhibitor xfce4-power-manager (xfce4-power-manager handles these events) pid=8611 uid=1000 mode=block stopped
systemd-logind[779]: Electing new display for user paulo
systemd-logind[779]: Ignoring session c8

logind config doesn't have anything that might cause this:

paulo:~$ loginctl show-session
EnableWallMessages=no
NAutoVTs=6
KillUserProcesses=no
RebootToFirmwareSetup=no
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0
BlockInhibited=handle-power-key:handle-suspend-key:handle-hibernate-key
DelayInhibited=sleep
InhibitDelayMaxUSec=5s
HandlePowerKey=poweroff
HandleSuspendKey=suspend
HandleHibernateKey=hibernate
HandleLidSwitch=suspend
HandleLidSwitchDocked=ignore
HoldoffTimeoutUSec=30s
IdleAction=ignore
IdleActionUSec=30min
PreparingForShutdown=no
PreparingForSleep=no
Docked=no
RemoveIPC=yes
RuntimeDirectorySize=615313408
InhibitorsMax=8192
NCurrentInhibitors=5
SessionsMax=8192
NCurrentSessions=1
UserTasksMax=10813

I can't find any anything that might cause an automatic logout after a time interval. I'm really stumped.

For intermittent X crash with SIGBUS on 18.04, please check this answer:

Ubuntu 18.04 error on waking up from sleep : Read-error on swap device

I have confirmed that this issue is caused by the Xorg server crashing with SIGBUS. Xorg server crashes and systemd-logind creates a new login session.

The Xorg server crashes because of an excessive number of requests from at-spi-bus-launcher. Right before each crash, messages such as these were logged on the systemd journal:

at-spi-bus-launcher[31720]: XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":0.0"
at-spi-bus-launcher[31720]: after 8065 requests (8065 known processed) with 0 events remaining.

It seems to be a documented issue, that Xorg crashes when it receives an excessive number of requests without interval.

To work around this bug, 2 steps are necessary:

1. Uninstall package at-spi2-core
   


2. Add export NO_AT_BRIDGE=1 to .profile, so that GTK applications don't complain about the absence of the accessibility bus

Xorg never crashed anymore after this workaround, and consequently there was no automatic logout anymore after resuming from suspend.

I filed a bug report against at-spi on the Gnome BugZilla.

When I think I nailed this issue, it bites me again :-(. The issue itself is indeed caused by the Xorg server crashing with SIGBUS, but the root cause of the crash is not at-spi-bus-launcher misbehaving. It shouldn't loop making those repeated requests, so the previous procedure is still valid, although it's not a workaround to the Xorg crash.

I discovered that Xorg was using kernel driver i915:

paulo:~$ sudo lshw -C video
 *-display
 description: VGA compatible controller
 product: 2nd Generation Core Processor Family Integrated Graphics Controller
 vendor: Intel Corporation
 physical id: 2
 bus info: pci@0000:00:02.0
 version: 09
 width: 64 bits
 clock: 33MHz
 capabilities: msi pm vga_controller bus_master cap_list rom
 configuration: driver=i915 latency=0
 resources: irq:36 memory:f6800000-f6bfffff memory:e0000000-efffffff ioport:f000(size=64) memory:c0000-dffff

So I tried another workaround, to force Xorg to use xserver-xorg-video-intel with acceleration method uxa, which is more stable than the default sna.

1. Create directory /etc/X11/xorg.conf.d. We can place xorg.conf snippets in this directory, and the Xorg server picks them up when it starts.


2. Create file /etc/X11/xorg.conf.d/10-intel.conf, directing Xorg to use its Intel video driver with acceleration method uxa.

Here's /etc/X11/xorg.conf.d/10-intel.conf:

Section "Device"
 Identifier "Intel Graphics"
 Driver "intel"
 Option "AccelMethod" "uxa"
EndSection

I have been using this workaround for 1 week and the Xorg server hasn't crashed, so I get the impression that it's the definitive workaround while Xorg isn't fixed.

I've opened a bug report against Xorg, which apparently seems to be affecting more users, since it was flagged as a duplicate of another bug, which I didn't detect at first since its title mentions another type of crash.