Created attachment 132297 [details]
GPU crash dump saved to /sys/class/drm/card0/error

I was asked to create a new bug since bug 100370 has been closed: https://bugs.freedesktop.org/show_bug.cgi?id=100370#c4

Currently everytime the machine wakes from suspend, the login screen appears but it does not work. I wait a little.
Sometimes it blinks and the login screen comes back to normal (I can type my password in the login box, wifi is connected in the network menu).
    But sometimes, a message about "runnning in low graphics mode" appears. It is possible to click OK and then the normal login screen comes back -- it may be necessary to click OK more than once.

This is on Ubuntu 16.04.2

--
Reminder of dmesg:

[50157.082931] [drm] GPU HANG: ecode 7:0:0x86ffbff9, in Xorg [11890], reason: Hang on render ring, action: reset
[50157.082933] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[50157.082933] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[50157.082934] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[50157.082934] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[50157.082935] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[50157.082990] drm/i915: Resetting chip after gpu hang