Comment # 8 on bug 93911 from David Breese

Thank you very much for pointing me to that, it looks right.  I didn't manage
to find it when searching the bug tracker.

I've now upgraded to kernel 4.4 which contains the relevant commit.  No more
crashes so far after 3 days of heavy use -- normally I would have expected a
crash sometime.

I'll post back if I do see the crash again, but provisionally I'll say this did
the trick.

Thanks!