OS: moblab 8172.27.0

What steps will reproduce the problem?
(1) run dut-control lid_open:no; sleep 45; dut-control lid_open:yes; sleep 45
(2)repeat 1 forever
(3) run export HOME=/tmp; screen -L /dev/pts/4 115200
to talk to EC console


What is the expected output?
test run and continuously 

What do you see instead?
Moblab rebooted with crash
2016-05-23T14:07:01.020622-07:00 WARNING kernel: [  306.625745] ------------[ cut here ]------------
2016-05-23T14:07:01.020651-07:00 WARNING kernel: [  306.625813] WARNING: CPU: 1 PID: 1772 at /mnt/host/source/src/third_party/kernel/v3.14/drivers/gpu/drm/i915/i915_gem.c:5125 i915_gem_obj_to_ggtt+0x4b/0x4f()
2016-05-23T14:07:01.021651-07:00 NOTICE kernel: [  306.625842] Modules linked in: uinput i2c_dev cmac x86_pkg_temp_thermal rfcomm memc_x86 aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd zram snd_soc_sst_acpi fuse ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat bridge stp llc smsc75xx usbnet ip6table_filter ip6_tables btusb btbcm btintel bluetooth iwlmvm iwl7000_mac80211 snd_hda_codec_realtek snd_hda_codec_generic iwlwifi snd_hda_codec_hdmi cfg80211 r8169 snd_hda_intel snd_hda_controller mii snd_hda_codec snd_hwdep snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device ppp_async ppp_generic slhc tun
2016-05-23T14:07:01.021673-07:00 NOTICE kernel: [  306.626111] CPU: 1 PID: 1772 Comm: CompositorTileW Tainted: G        W    3.14.0 #1
2016-05-23T14:07:01.021679-07:00 NOTICE kernel: [  306.626130] Hardware name: GOOGLE Guado, BIOS Google_Guado.6301.108.4 04/01/2015
2016-05-23T14:07:01.021685-07:00 NOTICE kernel: [  306.626146]  0000000000000000 00000000f7991ba7 ffff88006d461de8 ffffffffb4f9baa3
2016-05-23T14:07:01.021690-07:00 NOTICE kernel: [  306.626170]  0000000000000000 ffff88006d461e20 ffffffffb4a3df6b ffffffffb4ce4487
2016-05-23T14:07:01.021695-07:00 NOTICE kernel: [  306.626192]  ffff880076312300 0000000000000000 ffff8801799b8298 0000000040086200
2016-05-23T14:07:01.021698-07:00 NOTICE kernel: [  306.626214] Call Trace:
2016-05-23T14:07:01.021705-07:00 NOTICE kernel: [  306.626231]  [<ffffffffb4f9baa3>] dump_stack+0x4d/0x6f
2016-05-23T14:07:01.021714-07:00 NOTICE kernel: [  306.626250]  [<ffffffffb4a3df6b>] warn_slowpath_common+0x7f/0x98
2016-05-23T14:07:01.021721-07:00 NOTICE kernel: [  306.626267]  [<ffffffffb4ce4487>] ? i915_gem_obj_to_ggtt+0x4b/0x4f
2016-05-23T14:07:01.021727-07:00 NOTICE kernel: [  306.626286]  [<ffffffffb4a3e07d>] warn_slowpath_null+0x1a/0x1c
2016-05-23T14:07:01.021733-07:00 NOTICE kernel: [  306.626302]  [<ffffffffb4ce4487>] i915_gem_obj_to_ggtt+0x4b/0x4f
2016-05-23T14:07:01.021739-07:00 NOTICE kernel: [  306.626319]  [<ffffffffb4ce456b>] i915_gem_object_set_to_gtt_domain+0xe0/0x113
2016-05-23T14:07:01.021745-07:00 NOTICE kernel: [  306.626339]  [<ffffffffb4d341eb>] i915_gem_end_cpu_access+0x2e/0x42
2016-05-23T14:07:01.021751-07:00 NOTICE kernel: [  306.626358]  [<ffffffffb4d62697>] dma_buf_end_cpu_access+0x3f/0x44
2016-05-23T14:07:01.021757-07:00 NOTICE kernel: [  306.626375]  [<ffffffffb4d62990>] dma_buf_ioctl+0x8d/0xc5
2016-05-23T14:07:01.021762-07:00 NOTICE kernel: [  306.626391]  [<ffffffffb4b1cabf>] do_vfs_ioctl+0x355/0x416
2016-05-23T14:07:01.021768-07:00 NOTICE kernel: [  306.626406]  [<ffffffffb4b2527e>] ? __fget+0x6f/0x79
2016-05-23T14:07:01.021773-07:00 NOTICE kernel: [  306.626421]  [<ffffffffb4b1cbd7>] SyS_ioctl+0x57/0x79
2016-05-23T14:07:01.021779-07:00 NOTICE kernel: [  306.626439]  [<ffffffffb4fa0cdc>] system_call_fastpath+0x20/0x25
2016-05-23T14:07:01.021784-07:00 WARNING kernel: [  306.626453] ---[ end trace 1dcef025ce6488e6 ]---