Hi,

When shutting down my x220 laptop (intel sandy bridge) running a 4.4-rc8 
kernel, i encounter the splat below.
I have seen this in previous RC's, but christmas and thought i had seen 
patches related to vblank.

My .config is attached

--
Sander


Jan  5 22:42:17 x220 shutdown[10744]: shutting down for system halt
Jan  5 22:42:17 x220 init: Switching to runlevel: 0
Jan  5 22:42:18 x220 kernel: [42699.345756] ------------[ cut here 
]------------
Jan  5 22:42:18 x220 kernel: [42699.345772] WARNING: CPU: 1 PID: 3304 at 
drivers/gpu/drm/drm_irq.c:1268 drm_wait_one_vblank+0x136/0x180()
Jan  5 22:42:18 x220 kernel: [42699.345774] vblank wait timed out on 
crtc 0
Jan  5 22:42:18 x220 kernel: [42699.345831] Modules linked in: rfcomm 
ccm xt_tcpudp ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 
nf_defrag_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat 
ebtable_broute bridge stp llc ebtable_filter ebtables ip
Jan  5 22:42:18 x220 kernel: [42699.345883] CPU: 1 PID: 3304 Comm: Xorg 
Tainted: G     U          4.4.0-rc8-x220-20150104+ #1
Jan  5 22:42:18 x220 kernel: [42699.345885] Hardware name: LENOVO 
42912ZU/42912ZU, BIOS 8DET69WW (1.39 ) 07/18/2013
Jan  5 22:42:18 x220 kernel: [42699.345892]  ffffffff819daf40 
ffffffff81359e39 ffff8800d692f978 ffffffff81060297
Jan  5 22:42:18 x220 kernel: [42699.345895]  0000000000000000 
ffff8800d692f9c8 0000000000000000 00000000002665e7
Jan  5 22:42:18 x220 kernel: [42699.345898]  ffff88030f509408 
ffffffff81060317 ffffffff81a00570 0000000000000020
Jan  5 22:42:18 x220 kernel: [42699.345899] Call Trace:
Jan  5 22:42:18 x220 kernel: [42699.345912]  [<ffffffff81359e39>] ? 
dump_stack+0x40/0x57
Jan  5 22:42:18 x220 kernel: [42699.345917]  [<ffffffff81060297>] ? 
warn_slowpath_common+0x77/0xb0
Jan  5 22:42:18 x220 kernel: [42699.345920]  [<ffffffff81060317>] ? 
warn_slowpath_fmt+0x47/0x50
Jan  5 22:42:18 x220 kernel: [42699.345925]  [<ffffffff81479736>] ? 
drm_wait_one_vblank+0x136/0x180
Jan  5 22:42:18 x220 kernel: [42699.345933]  [<ffffffff81097690>] ? 
wait_woken+0x80/0x80
Jan  5 22:42:18 x220 kernel: [42699.345941]  [<ffffffff815002f8>] ? 
intel_atomic_commit+0x428/0x12c0
Jan  5 22:42:18 x220 kernel: [42699.345950]  [<ffffffff8146ee7f>] ? 
drm_atomic_helper_check_planes+0x12f/0x1a0
Jan  5 22:42:18 x220 kernel: [42699.345954]  [<ffffffff8148fdea>] ? 
drm_atomic_check_only+0x13a/0x5c0
Jan  5 22:42:18 x220 kernel: [42699.345958]  [<ffffffff8148fbed>] ? 
drm_atomic_add_affected_connectors+0x1d/0xe0
Jan  5 22:42:18 x220 kernel: [42699.345964]  [<ffffffff81470527>] ? 
restore_fbdev_mode+0x227/0x250
Jan  5 22:42:18 x220 kernel: [42699.345967]  [<ffffffff8148ec82>] ? 
drm_modeset_lock_all_crtcs+0x82/0x90
Jan  5 22:42:18 x220 kernel: [42699.345973]  [<ffffffff814726e9>] ? 
drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x70
Jan  5 22:42:18 x220 kernel: [42699.345978]  [<ffffffff81472754>] ? 
drm_fb_helper_set_par+0x24/0x50
Jan  5 22:42:18 x220 kernel: [42699.345984]  [<ffffffff81515f61>] ? 
intel_fbdev_set_par+0x11/0x60
Jan  5 22:42:18 x220 kernel: [42699.345990]  [<ffffffff813c19a9>] ? 
fb_set_var+0x159/0x380
Jan  5 22:42:18 x220 kernel: [42699.345996]  [<ffffffff811d1f05>] ? 
ext4_mark_iloc_dirty+0x495/0x750
Jan  5 22:42:18 x220 kernel: [42699.346004]  [<ffffffff8120c0fa>] ? 
__jbd2_journal_file_buffer+0xda/0x1c0
Jan  5 22:42:18 x220 kernel: [42699.346009]  [<ffffffff811f2a71>] ? 
__ext4_journal_get_write_access+0x31/0x70
Jan  5 22:42:18 x220 kernel: [42699.346017]  [<ffffffff813b9188>] ? 
fbcon_blank+0x1f8/0x2b0
Jan  5 22:42:18 x220 kernel: [42699.346026]  [<ffffffff8143b1be>] ? 
do_unblank_screen+0xae/0x1b0
Jan  5 22:42:18 x220 kernel: [42699.346030]  [<ffffffff81432746>] ? 
vt_ioctl+0x656/0x1260
Jan  5 22:42:18 x220 kernel: [42699.346035]  [<ffffffff811f2cd9>] ? 
__ext4_handle_dirty_metadata+0x79/0x1d0
Jan  5 22:42:18 x220 kernel: [42699.346040]  [<ffffffff81427731>] ? 
tty_ioctl+0x3b1/0xc00
Jan  5 22:42:18 x220 kernel: [42699.346048]  [<ffffffff8116a31f>] ? 
do_vfs_ioctl+0x2bf/0x4a0
Jan  5 22:42:18 x220 kernel: [42699.346052]  [<ffffffff8116a571>] ? 
SyS_ioctl+0x71/0x80
Jan  5 22:42:18 x220 kernel: [42699.346058]  [<ffffffff8100304d>] ? 
exit_to_usermode_loop+0x4d/0xa0
Jan  5 22:42:18 x220 kernel: [42699.346067]  [<ffffffff816fb4b6>] ? 
entry_SYSCALL_64_fastpath+0x16/0x75
Jan  5 22:42:18 x220 kernel: [42699.346071] ---[ end trace 
8485dd9d3f1f4ad2 ]---
Jan  5 22:42:18 x220 rsyslogd-2007: action 'action 17' suspended, next 
retry is Tue Jan  5 22:42:48 2016 [try http://www.rsyslog.com/e/2007 ]
Jan  5 22:42:18 x220 acpid: client 3304[0:0] has disconnected
Jan  5 22:42:18 x220 acpid: client connected from 10751[0:0]
Jan  5 22:42:18 x220 acpid: 1 client rule loaded
Jan  5 22:42:18 x220 bluetoothd[2392]: Terminating
Jan  5 22:42:18 x220 pkcsslotd: Exiting on SIGTERM (15; 0xf)
Jan  5 22:42:19 x220 NetworkManager[2442]: <info> caught signal 15, 
shutting down normally.
Jan  5 22:42:19 x220 NetworkManager[2442]: <info> (eth0): device state 
change: unavailable -> unmanaged (reason 'removed') [20 10 36]
Jan  5 22:42:19 x220 bluetoothd[2392]: Stopping SDP server

.....

Jan  5 22:42:19 x220 dbus[2343]: [system] Activating service 
name='org.freedesktop.nm_dispatcher' (using servicehelper)
Jan  5 22:42:19 x220 NetworkManager[2442]: <info> exiting (success)
Jan  5 22:42:19 x220 dbus[2343]: [system] Successfully activated service 
'org.freedesktop.nm_dispatcher'
Jan  5 22:42:21 x220 kernel: [42703.097999] [drm:i915_hangcheck_elapsed] 
*ERROR* Hangcheck timer elapsed... blitter ring idle
Jan  5 22:42:22 x220 kernel: [42703.553747] ------------[ cut here 
]------------
Jan  5 22:42:22 x220 kernel: [42703.558646] WARNING: CPU: 2 PID: 10751 
at drivers/gpu/drm/drm_irq.c:1268 drm_wait_one_vblank+0x136/0x180()
Jan  5 22:42:22 x220 kernel: [42703.567419] vblank wait timed out on 
crtc 0
Jan  5 22:42:22 x220 kernel: [42703.572058] Modules linked in: rfcomm 
ccm bridge stp llc input_polldev x_tables bnep binfmt_misc nfsd 
auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc uvcvideo 
videobuf2_vmalloc intel_rapl videobuf2_memops iosf_mbi snd
Jan  5 22:42:22 x220 kernel: [42703.674298] CPU: 2 PID: 10751 Comm: Xorg 
Tainted: G     U  W       4.4.0-rc8-x220-20150104+ #1
Jan  5 22:42:22 x220 kernel: [42703.678305] Hardware name: LENOVO 
42912ZU/42912ZU, BIOS 8DET69WW (1.39 ) 07/18/2013
Jan  5 22:42:22 x220 kernel: [42703.679811]  ffffffff819daf40 
ffffffff81359e39 ffff8802e00a3b48 ffffffff81060297
Jan  5 22:42:22 x220 kernel: [42703.681518]  0000000000000000 
ffff8802e00a3b98 0000000000000000 00000000002666e4
Jan  5 22:42:22 x220 kernel: [42703.683350]  ffff88030f509408 
ffffffff81060317 ffffffff81a00570 0000000000000020
Jan  5 22:42:22 x220 kernel: [42703.684805] Call Trace:
Jan  5 22:42:22 x220 kernel: [42703.685433]  [<ffffffff81359e39>] ? 
dump_stack+0x40/0x57
Jan  5 22:42:22 x220 kernel: [42703.686604]  [<ffffffff81060297>] ? 
warn_slowpath_common+0x77/0xb0
Jan  5 22:42:22 x220 kernel: [42703.687922]  [<ffffffff81060317>] ? 
warn_slowpath_fmt+0x47/0x50
Jan  5 22:42:22 x220 kernel: [42703.689362]  [<ffffffff81479736>] ? 
drm_wait_one_vblank+0x136/0x180
Jan  5 22:42:22 x220 kernel: [42703.690695]  [<ffffffff81097690>] ? 
wait_woken+0x80/0x80
Jan  5 22:42:22 x220 kernel: [42703.691911]  [<ffffffff815002f8>] ? 
intel_atomic_commit+0x428/0x12c0
Jan  5 22:42:22 x220 kernel: [42703.693489]  [<ffffffff8146ee7f>] ? 
drm_atomic_helper_check_planes+0x12f/0x1a0
Jan  5 22:42:22 x220 kernel: [42703.694974]  [<ffffffff8148fdea>] ? 
drm_atomic_check_only+0x13a/0x5c0
Jan  5 22:42:22 x220 kernel: [42703.696488]  [<ffffffff814e92ee>] ? 
intel_crtc_duplicate_state+0x2e/0x40
Jan  5 22:42:22 x220 kernel: [42703.697944]  [<ffffffff8148f224>] ? 
drm_atomic_get_crtc_state+0x24/0xb0
Jan  5 22:42:22 x220 kernel: [42703.699485]  [<ffffffff8146f4e1>] ? 
drm_atomic_helper_disable_plane+0xa1/0xe0
Jan  5 22:42:22 x220 kernel: [42703.701156]  [<ffffffff81481d97>] ? 
__setplane_internal+0x177/0x290
Jan  5 22:42:22 x220 kernel: [42703.702506]  [<ffffffff8148ec82>] ? 
drm_modeset_lock_all_crtcs+0x82/0x90
Jan  5 22:42:22 x220 kernel: [42703.704041]  [<ffffffff81484a47>] ? 
drm_mode_setplane+0x137/0x1b0
Jan  5 22:42:22 x220 kernel: [42703.705393]  [<ffffffff81477d31>] ? 
drm_ioctl+0x121/0x490
Jan  5 22:42:22 x220 kernel: [42703.706610]  [<ffffffff81484910>] ? 
drm_plane_check_pixel_format+0x40/0x40
Jan  5 22:42:22 x220 kernel: [42703.708210]  [<ffffffff810976c0>] ? 
autoremove_wake_function+0x30/0x30
Jan  5 22:42:22 x220 kernel: [42703.709599]  [<ffffffff8116a31f>] ? 
do_vfs_ioctl+0x2bf/0x4a0
Jan  5 22:42:22 x220 kernel: [42703.710858]  [<ffffffff810697be>] ? 
recalc_sigpending+0xe/0x50
Jan  5 22:42:22 x220 kernel: [42703.712246]  [<ffffffff8106a248>] ? 
__set_task_blocked+0x28/0x70
Jan  5 22:42:22 x220 kernel: [42703.713575]  [<ffffffff8116a571>] ? 
SyS_ioctl+0x71/0x80
Jan  5 22:42:22 x220 kernel: [42703.714728]  [<ffffffff8106c7b0>] ? 
SyS_rt_sigprocmask+0x60/0xa0
Jan  5 22:42:22 x220 kernel: [42703.716141]  [<ffffffff816fb4b6>] ? 
entry_SYSCALL_64_fastpath+0x16/0x75
Jan  5 22:42:22 x220 kernel: [42703.717564] ---[ end trace 
8485dd9d3f1f4ad3 ]---
Jan  5 22:42:23 x220 kernel: [42703.869731] ------------[ cut here 
]------------

....

Jan  5 22:42:23 x220 kernel: [42703.869731] ------------[ cut here 
]------------
Jan  5 22:42:23 x220 kernel: [42703.869746] WARNING: CPU: 2 PID: 10751 
at drivers/gpu/drm/drm_irq.c:1268 drm_wait_one_vblank+0x136/0x180()
Jan  5 22:42:23 x220 kernel: [42703.869747] vblank wait timed out on 
crtc 0
Jan  5 22:42:23 x220 kernel: [42703.869815] Modules linked in: rfcomm 
ccm bridge stp llc input_polldev x_tables bnep binfmt_misc nfsd 
auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc uvcvideo 
videobuf2_vmalloc intel_rapl videobuf2_memops iosf_mbi snd
Jan  5 22:42:23 x220 kernel: [42703.869834] CPU: 2 PID: 10751 Comm: Xorg 
Tainted: G     U  W       4.4.0-rc8-x220-20150104+ #1
Jan  5 22:42:23 x220 kernel: [42703.869836] Hardware name: LENOVO 
42912ZU/42912ZU, BIOS 8DET69WW (1.39 ) 07/18/2013
Jan  5 22:42:23 x220 kernel: [42703.869842]  ffffffff819daf40 
ffffffff81359e39 ffff8802e00a3978 ffffffff81060297
Jan  5 22:42:23 x220 kernel: [42703.869845]  0000000000000000 
ffff8802e00a39c8 0000000000000000 00000000002666f7
Jan  5 22:42:23 x220 kernel: [42703.869848]  ffff88030f509408 
ffffffff81060317 ffffffff81a00570 0000000000000020
Jan  5 22:42:23 x220 kernel: [42703.869850] Call Trace:
Jan  5 22:42:23 x220 kernel: [42703.869862]  [<ffffffff81359e39>] ? 
dump_stack+0x40/0x57
Jan  5 22:42:23 x220 kernel: [42703.869867]  [<ffffffff81060297>] ? 
warn_slowpath_common+0x77/0xb0
Jan  5 22:42:23 x220 kernel: [42703.869869]  [<ffffffff81060317>] ? 
warn_slowpath_fmt+0x47/0x50
Jan  5 22:42:23 x220 kernel: [42703.869874]  [<ffffffff81479736>] ? 
drm_wait_one_vblank+0x136/0x180
Jan  5 22:42:23 x220 kernel: [42703.869881]  [<ffffffff81097690>] ? 
wait_woken+0x80/0x80
Jan  5 22:42:23 x220 kernel: [42703.869889]  [<ffffffff815002f8>] ? 
intel_atomic_commit+0x428/0x12c0
Jan  5 22:42:23 x220 kernel: [42703.869898]  [<ffffffff8146ee7f>] ? 
drm_atomic_helper_check_planes+0x12f/0x1a0
Jan  5 22:42:23 x220 kernel: [42703.869902]  [<ffffffff8148fdea>] ? 
drm_atomic_check_only+0x13a/0x5c0
Jan  5 22:42:23 x220 kernel: [42703.869906]  [<ffffffff8148fbed>] ? 
drm_atomic_add_affected_connectors+0x1d/0xe0
Jan  5 22:42:23 x220 kernel: [42703.869912]  [<ffffffff81470527>] ? 
restore_fbdev_mode+0x227/0x250
Jan  5 22:42:23 x220 kernel: [42703.869915]  [<ffffffff8148ec82>] ? 
drm_modeset_lock_all_crtcs+0x82/0x90
Jan  5 22:42:23 x220 kernel: [42703.869921]  [<ffffffff814726e9>] ? 
drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x70
Jan  5 22:42:23 x220 kernel: [42703.869926]  [<ffffffff81472754>] ? 
drm_fb_helper_set_par+0x24/0x50
Jan  5 22:42:23 x220 kernel: [42703.869931]  [<ffffffff81515f61>] ? 
intel_fbdev_set_par+0x11/0x60
Jan  5 22:42:23 x220 kernel: [42703.869937]  [<ffffffff813c19a9>] ? 
fb_set_var+0x159/0x380
Jan  5 22:42:23 x220 kernel: [42703.869942]  [<ffffffff8135f38e>] ? 
radix_tree_lookup_slot+0xe/0x20
Jan  5 22:42:23 x220 kernel: [42703.869949]  [<ffffffff810f66d4>] ? 
find_get_entry+0x14/0x70
Jan  5 22:42:23 x220 kernel: [42703.869959]  [<ffffffff813b9188>] ? 
fbcon_blank+0x1f8/0x2b0
Jan  5 22:42:23 x220 kernel: [42703.869967]  [<ffffffff8143b1be>] ? 
do_unblank_screen+0xae/0x1b0
Jan  5 22:42:23 x220 kernel: [42703.869971]  [<ffffffff81432746>] ? 
vt_ioctl+0x656/0x1260
Jan  5 22:42:23 x220 kernel: [42703.869978]  [<ffffffff811f2cd9>] ? 
__ext4_handle_dirty_metadata+0x79/0x1d0
Jan  5 22:42:23 x220 kernel: [42703.869983]  [<ffffffff81427731>] ? 
tty_ioctl+0x3b1/0xc00
Jan  5 22:42:23 x220 kernel: [42703.869991]  [<ffffffff8116a31f>] ? 
do_vfs_ioctl+0x2bf/0x4a0
Jan  5 22:42:23 x220 kernel: [42703.869995]  [<ffffffff8116a571>] ? 
SyS_ioctl+0x71/0x80
Jan  5 22:42:23 x220 kernel: [42703.870001]  [<ffffffff8100304d>] ? 
exit_to_usermode_loop+0x4d/0xa0
Jan  5 22:42:23 x220 kernel: [42703.870010]  [<ffffffff816fb4b6>] ? 
entry_SYSCALL_64_fastpath+0x16/0x75
Jan  5 22:42:23 x220 kernel: [42703.870013] ---[ end trace 
8485dd9d3f1f4ad4 ]---
Jan  5 22:42:23 x220 nm-dispatcher: Caught signal 15, shutting down...