Dear Maintainer,

Recent version of gdm3 uses gnome-shell in wayland mode to display its
interface. On my acer aspire s3-371 Ultrabook, if I log out from an X session
to gdm3's login interface, or locks the x-session down and switches to gdm3's
wayland-powered unlocking interface, and wait until the screen is closed for
power-saving, the screen may never be lit up with actions normally able to wake
it from power-saving, such as key-pressing, mouse-moving, or trackpad-tapping.
Even ctrl-alt-F1~F6 cannot bring the screen back from complete blackout. If the
problem occurs, the laptop becomes completely unoperable locally. The only way
to bring the laptop operable is to login from another machine via ssh, and
restart gdm3.

If I never login to any x-sessions and stay on gdm3's login interface, the
problem never happens any more and screen can always be woken up from power-saving.

Now I have to disable wayland usage in gdm3's config file, and similar problem
never happens. This problem only affects this acer aspire s3-371 Ultrabook,
never observed on my other machines with 2nd gen core i running similar-
configured Debian GNU/Linux.

This bug may have to be reassigned to gnome-shell, since it is gnome-shell that
works as the display server in wayland mode, but I have never used wayland
outside gdm3 (I always use X).

Outputs from lscpu, lspci, dmidecode and dmesg on my acer aspire s3-371 will be
attached.