Comment 23 for bug 1649566

Dieter Maurer:
>"It may take a bit of time before I can make the tests with the current Ubuntu version."

If the problem is reproducible in a live environment, then testing that would be fine.

>"And, I fear that such tests might not be reliable: after the temporary use of the NVidia driver I could use the "nouveau" driver for some time even without the special boot parameter "nouveau.config=NvMSI=0" - only after some months, new freezes occurred."

Such test is reliable, in that it provides additional data points with later versions of various related packages. This is required in order to upstream an issue for upstream developers to address.

Despite this, if one notices different environment behavior with nouveau after such maneuvering, the proprietary driver may be twiddling some bits that luckily improve stability after removal. It could also be a coincedence.

>"I have the feeling that the problem (now) arises non-deterministically -- likely dependent on environment factors such as temperature and/or humidity."

Evidence and data are helpful, guesses/feelings/hunches aren't. One may monitor internal temperatures via https://help.ubuntu.com/community/SensorInstallHowto in order to prove a correlation.

>"While freezes are now rather rare for me, I often observe that the top bars of my windows (usually black) are drawn in an irregular black/white pattern (similar to the freeze pattern) when I move the mouse pointer over the bar."

This report is scoped to freezing/crashing. If you are having graphical issues without freezing/crashing that's a different problem for a new report. Feel free to file a new one scoped to that and subscribe me to it.