Ubuntu: intel graphics features stop working in 17.04 while using Intel Graphics Update Tool

mentioning this as it stopped me in my tracks for 2 or 3 hours while I
stuffed around reading logs and disconnecting monitors etc…

I did a routine update/reboot and my multimonitor and 3D etc stopped
working.

This is on Xubuntu 17.04 with the more current Intel graphic stack from https://01.org/linuxgraphics/downloads/intel-graphics-update-tool-linux-os-v2.0.5 loaded so I can get all the Kaby Lake goodness with my my motherboard and CPU

Symptom: in dmesg I had

dmesg | grep drm
[ 0.832828] drm: loading out-of-tree module taints kernel.
[ 0.832941] drm: module verification failed: signature and/or
required key missing - tainting kernel
[ 0.850622] i915: Unknown symbol drm_mm_init_scan_with_range (err 0)
[ 0.850653] i915: Unknown symbol drm_kms_helper_poll_enable_locked
(err 0)
[ 0.850684] i915: Unknown symbol drm_crtc_get_hv_timing (err 0)
[ 0.850828] i915: Unknown symbol drm_mm_init_scan (err 0)
[ 0.850869] i915: Unknown symbol drm_mm_insert_node_in_range_generic
(err 0)
[ 3.204261] i915: Unknown symbol drm_mm_init_scan_with_range (err 0)
[ 3.204421] i915: Unknown symbol drm_kms_helper_poll_enable_locked
(err 0)
[ 3.204770] i915: Unknown symbol drm_crtc_get_hv_timing (err 0)
[ 3.205409] i915: Unknown symbol drm_mm_init_scan (err 0)
[ 3.205560] i915: Unknown symbol drm_mm_insert_node_in_range_generic
(err 0)
[ 3.243085] i915: Unknown symbol drm_mm_init_scan_with_range (err 0)
[ 3.243271] i915: Unknown symbol drm_kms_helper_poll_enable_locked
(err 0)
[ 3.243466] i915: Unknown symbol drm_crtc_get_hv_timing (err 0)
[ 3.244200] i915: Unknown symbol drm_mm_init_scan (err 0)
[ 3.244371] i915: Unknown symbol drm_mm_insert_node_in_range_generic
(err 0)

while a working box has


dmesg | grep drm
[ 1.082758] [drm] Initialized
[ 1.247377] [drm] Memory usable by graphics device = 2048M
[ 1.247381] fb: switching to inteldrmfb from VESA VGA
[ 1.247534] [drm] Replacing VGA console driver
[ 1.256114] [drm] Supports vblank timestamp caching Rev 2
(21.10.2013).
[ 1.256116] [drm] Driver supports precise vblank timestamp query.
[ 1.276738] [drm] RC6 disabled, disabling runtime PM support
[ 1.286326] [drm] Initialized i915 1.6.0 20161121 for 0000:00:02.0
on minor 0
[ 1.329495] fbcon: inteldrmfb (fb0) is primary device
[ 1.329623] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device

Fix (after reading thru https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1722536 )

apt-get remove i915-4.11.6-4.10.0-dkms
apt-get install i915-4.11.6-4.10.0-dkms

to force a rebuild of this kernel module.. running the intel graphics
updater wont do it as it thinks its fine, but it refuses to load…