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

[Theodore Ts'o]

On Mon, Dec 08, 2014 at 12:32:01PM +1000, Dave Airlie wrote:
> 
> I suspect a lot of the problems are just that xfce isn't sufficiently handling
> randr events, and it is getting out of sync, it is like hotplug networking
> before NetworkManager etc.

Yes, I've seen this on XFCE 4.11 (in Ubuntu), although I haen't seen
it in XFCE 4.10 (in Debian).  In 4.11, when xfce gets out of sync,
xrandr --auto will allow me to enable the display, even when
xfce4-display-settings does not.

However, on my T540p with the monitors connected via the dock, which
is the problem I was describing here, xrandr --auto does *not* fix
things up.  So I think it's a different problem, since I can see this
problem even if I don't use xfce4-display-settings, and just use
xrandr directly.

						- Ted