[regression] i965 graphics corruption after recent xenial updates

[Tigran Aivazian]

I am using Ubuntu 16.04.4 LTS. Since the original release two years ago it was working absolutely fine on a variety of machines. Now, on this particular machine I have two monitors:

1. Dell 24" 1200x1920 (portrait) connected via D-SUB/VGA port
2. AOC 28" 1920x1080 (landscape) connected via DVI-D

I have made an upgrade today and the following packages were upgraded:

https://paste.ubuntu.com/p/5cf8hq6JQK/

Note that the list includes mesa libraries and xserver-xorg* packages which are most suspect.

Here is my /var/log/Xorg.0.log:

https://paste.ubuntu.com/p/tB6yGhDT2S/

Here is the output of "sudo lspci -vvx":

https://paste.ubuntu.com/p/VVctSFwFSm/

As you can see, there is nothing special about this machine: a pretty vanilla desktop with i5-3570K cpus (NOT overclocked!) and 16GB RAM. Oh, I forgot to say what actually happens and why the system is unusable: even if I create a single gnome-terminal window (say on the Dell monitor) after a couple of seconds (of typing in the terminal) large size rectangles appear on the other monitor. And if I start Chrome (on a monitor different from the one gnome-terminal is running on) then bits of the terminal sometimes appear on one of Chrome's tabs and vice versa, i.e. bits (rectangular shape) of Chrome's tabs appear on the terminal. Sometimes the content of the terminal gets corrupted. And all this happens reasonably quickly (on the order of 5-10 seconds), which means you can't do any work at all. Also, creating other windows (I started pavucontrol in the background) makes the mess even worse, i.e. they all keep overwriting each other's rendering context.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1780449/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Tigran Aivazian (aivazian-tigran)]

I would like to add that in Ubuntu 18.04 this problem does NOT exist. However, at the moment I am not able to upgrade to 18.04 because of many other problems with 18.04 (e.g. printing doesn't work etc etc). These are not insurmountable problems, but will take some time to fix and then I should be able to just move to Ubuntu 18.04.

[Daniel van Vugt (vanvugt)]

Please:

1. Run 'apport-collect 1780449' to send us more information about the machine.

2. Take a photo of the corruption and attach it here.

[Tigran Aivazian (aivazian-tigran)]

I don't use apport infrastructure because I always uninstall such things ("security" etc) after installation of Ubuntu, which makes it boot about 20 times faster (0.9 seconds vs 15 seconds).

However, I am a Linux kernel developer with more than 20 years' experience, so I am sure I can provide all the information you require manually. What else do you need to see, other than lspci -vvx and Xorg.0.log which I have provided already?

[Daniel van Vugt (vanvugt)]

In that case please start by trying older versions of mesa to see if that caused the problem.

I would hazard a guess that downgrading to the previous version:
 https://launchpad.net/ubuntu/+source/mesa/17.2.8-0ubuntu0~16.04.1
might fix the problem...?