Comment 7 for bug 1871687

I'm not finding much in the logs. There's some i915 splat which could possibly be related to the corruption, but nothing to explain the hard lockup.

The current focal-proposed kernel (5.4.0-24) has some fixes for races/deadlocks in i915, so it's worth trying that out to see if it helps. You can use ppa:canonical-kernel-team/proposed to get that kernel.