WARNING: /usr/projects/linux/linux/drivers/gpu/drm/i915/intel_pm.c:6585 intel_display_power_put+0x4b/0x116 [i915]()

[Theodore Ts'o]

This morning, I was docked and using a Dell 30" monitor.  I
reconfigured the X server to stop sending video to the external
monitor, suspended the laptop, and after it was suspended undocked it
and took it to work.  Then I docked it at work, where it was connected
to a powered off Dell 24" monitor.

Since this time there was a note:

[drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[drm] GPU crash dump saved to /sys/class/drm/card0/error

I've filed:

	https://bugs.freedesktop.org/show_bug.cgi?id=87327

I do want to note that this is only one of many different symptoms and
failures that I am seeing.

Basically, after suspending and resuming, if I use an external
monitor, I have to be prepared to restart the X server --- and
sometimes the kernel will sponaneously reboot, sometimes when I do
something as simple as accidentally brushing against the power switch
on the Dell montor.   :-(   :-(   :-(

					- Ted