Comment 67 for bug 1798961

I had been experiencing the freeze/lockup on 18.10. My main machine is a Lenovo ThinkPad laptop with switchable graphics (Intel & Nvidia), and Intel Xeon E-2176M CPU.

Originally, my guess was that the lockup was graphics related. Back in March 2019, I applied the xorg.conf edits recommended in comment #42. This seemed to eliminate the hard freezes, at least for a while. However, not long ago, perhaps around mid-June, the freezes returned. Also, I encountered the freezes not only with Intel graphics engaged, but when the system was using the discrete Nvidia chip too. I tried to correlate the freezing with use of Chromium, but it occurred using Firefox too, and in fact happened with no browser running.

As a last ditch attempt to avoid re-installation, I upgraded the system from 18.10 ~> 19.04, hopeful that kernel version 5 would make the situation better. In my case, this has been so. //Since upgrading to 19.04, and running various increments of kernel 5 (5.0.0-[17,19,20]-generic,) I haven't encountered any freezes// 5 days now and counting (FWIW)

From reading prior posts, seems some folks are already using kernel 5, and their freeze problem remains. Nevertheless, for my case, with a laptop with newer hardware, upgrading Ubuntu and kernel version was helpful.

I had accumulated a collection of crash dumps from my old Ubuntu version (18.10 and kernel 4.18), which I will attach to the ticket. Hopefully they might be of use for investigation.