longstanding display driver bug elicited by xscreensaver or lightdm or chvt

[gregrwm]

i've been hitting this bug since natty or earlier. today, as per usual, the evidence of the bug is that chvt no longer functions normally. in today's case, two instances of xorg had been running, both crashed, xorg would not relaunch (immediately crashed again)(tho no trouble launching Xvnc), after the xorg crashes ctl-alt-F7 shows: "The system is running in low-graphics mode", ctl-alt-F8 shows all black, and the clear clue, ctl-alt-F1 shows the text you would expect to see there, but at the same time the mouse cursor is still being displayed and responding to mouse movement as if we were still looking at ctl-alt-F[78]! same for ctl-alt-F[2-6]. when i hit this same bug on other days, the behaviour of ctl-alt-Fn will be peculiar in unique bizarre ways.

i tried to submit this bug via ubuntu-bug (in 2 or 3 "screen" windows, then killed them all, then tried one more time), then zipped up the apport log, the Xorg logs, the single /var/crash/*Xorg* i found, and a process list.

[penalvch (penalvch)]

gregrwm, thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect -p xorg 1290797

Please ensure you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information.

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Launchpad Janitor (janitor)]

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

[gregrwm (gregrwm)]

in all of the following bugs, xorg either crashes or hangs, and ctl-alt-Fn either doesn't respond (ie loss of ability to change virtual terminal from the keyboard) or in Bug #1290797 the text gets switched but not the mouse cursor function.

Bug #1757299 xorg hangs
Bug #1744429 xorg sometimes freezes up while playing either vlc or youtube
Bug #1645485 very old display driver bug?
Bug #1290797 longstanding display driver bug elicited by xscreensaver or lightdm or chvt

i have xdiagnose installed in bionic, ready for the next occurrence.

[penalvch (penalvch)]

gregrwm, reviewing your attachment, it is noticed that your crash report is manually attached.

Please follow these instructions to have apport report a new bug against your crash file that can be dealt with by the automatic retracer. First, execute at a terminal:
cd /var/crash && sudo rm * ; sudo apt-get update && sudo apt-get -y dist-upgrade && sudo service apport start force_start=1

If you are running the Ubuntu Stable Release you might need to enable apport in /etc/default/apport and restart. Now reproduce the crash, then open a terminal, navigate to your /var/crash directory and file your report with:
sudo ubuntu-bug /var/crash/_my_crash_report.crash

where _my_crash_report.crash is the crash you would like to report. By default, this sends the crash to the Ubuntu Error Tracker infrastructure, which is different than Launchpad. For more on this, please see https://wiki.ubuntu.com/ErrorTracker .

However, this report is being closed since the process outlined above will deal with this issue more efficiently.

Also, please do not attach your crash report manually to this report and reopen it.

Thank you for your help.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs