Dear Maintainer,

I have noticed my laptop fail to fully resume from sleep several times.  On
this occasion, I used the sleep key combination (Fn Backspace) to put it to
sleep and then closed the lid.  Hours later, I opened the lid and pressed
the control key.  The lightdm unlock screen appeared correctly.  I entered
my password and the unlock screen was replaced with a blank black screen.
When I switched to a text console using Ctrl+Alt+F2, I was able to login
and run commands, but when I switched back to console 7, the screen went
black again.  I would expect my windows to appear.

This problem doesn't always occur.  It's not clear what the difference is
between times when it occurs and times when it doesn't.

Thanks for looking at this problem.

Kind regards,
Neil.