Comment 21 for bug 1384297

how about 16.04? It does not hang any more, but the message is still repeated many times in the dmesg log:

[ 1.940071] ------------[ cut here ]------------
[ 1.940109] WARNING: CPU: 1 PID: 6 at /build/linux-Ay7j_C/linux-4.4.0/drivers/gpu/drm/drm_irq.c:1326 drm_wait_one_vblank+0x1b5/0x1c0 [drm]()
[ 1.940113] vblank wait timed out on crtc 0
[ 1.940116] Modules linked in: hid_generic usbhid hid i915 psmouse ahci i2c_algo_bit firewire_ohci libahci sdhci_pci pata_acpi sdhci firewire_core drm_kms_helper crc_itu_t syscopyarea sysfillrect ssb sysimgblt fb_sys_fops sky2 drm wmi fjes video
[ 1.940155] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 4.4.0-21-generic #37-Ubuntu
[ 1.940158] Hardware name: Dell Inc. Inspiron 1525 /0U990C, BIOS A17 10/27/2009
[ 1.940166] Workqueue: events_unbound async_run_entry_fn
[ 1.940171] 0000000000000286 00000000601d6afd ffff8800bb7f7a08 ffffffff813e93c3
[ 1.940177] ffff8800bb7f7a50 ffffffffc0058b10 ffff8800bb7f7a40 ffffffff81080f62
[ 1.940188] ffff880035df3800 0000000000000000 0000000000000000 0000000000000003
[ 1.940191] Call Trace:
[ 1.940197] [<ffffffff813e93c3>] dump_stack+0x63/0x90
[ 1.940202] [<ffffffff81080f62>] warn_slowpath_common+0x82/0xc0
[ 1.940204] [<ffffffff81080ffc>] warn_slowpath_fmt+0x5c/0x80
[ 1.940209] [<ffffffff810c3575>] ? finish_wait+0x55/0x70
[ 1.940224] [<ffffffffc00292a5>] drm_wait_one_vblank+0x1b5/0x1c0 [drm]
[ 1.940227] [<ffffffff810c3a10>] ? wake_atomic_t_function+0x60/0x60
[ 1.940285] [<ffffffffc0208339>] intel_get_load_detect_pipe+0x529/0x530 [i915]
[ 1.940325] [<ffffffffc02418ed>] intel_tv_detect+0x13d/0x5f0 [i915]
[ 1.940341] [<ffffffffc00e7da5>] drm_helper_probe_single_connector_modes_merge_bits+0x235/0x4d0 [drm_kms_helper]
[ 1.940349] [<ffffffffc00e8053>] drm_helper_probe_single_connector_modes+0x13/0x20 [drm_kms_helper]
[ 1.940358] [<ffffffffc00f491e>] drm_fb_helper_initial_config+0xae/0x420 [drm_kms_helper]
[ 1.940396] [<ffffffffc02184bb>] intel_fbdev_initial_config+0x1b/0x20 [i915]
[ 1.940399] [<ffffffff810a2f28>] async_run_entry_fn+0x48/0x150
[ 1.940402] [<ffffffff81099ff2>] process_one_work+0x162/0x480
[ 1.940405] [<ffffffff8109a35b>] worker_thread+0x4b/0x4c0
[ 1.940408] [<ffffffff8109a310>] ? process_one_work+0x480/0x480
[ 1.940411] [<ffffffff810a0528>] kthread+0xd8/0xf0
[ 1.940414] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 1.940418] [<ffffffff8182488f>] ret_from_fork+0x3f/0x70
[ 1.940420] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 1.940423] ---[ end trace f06ce4fed187d576 ]---
[ 1.946160] sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 sda9 >
[ 1.947069] sd 2:0:0:0: [sda] Attached SCSI disk
[ 2.016251] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x39834d15f18, max_idle_ns: 881590752306 ns
[ 2.072400] firewire_core 0000:02:09.0: created device fw0: GUID 444fc0000d6981e1, S400
[ 2.084258] ------------[ cut here ]------------
[ 2.084291] WARNING: CPU: 1 PID: 6 at /build/linux-Ay7j_C/linux-4.4.0/drivers/gpu/drm/drm_irq.c:1326 drm_wait_one_vblank+0x1b5/0x1c0 [drm]()
[ 2.084295] vblank wait timed out on crtc 0
[ 2.084297] Modules linked in: hid_generic usbhid hid i915 psmouse ahci i2c_algo_bit firewire_ohci libahci sdhci_pci pata_acpi sdhci firewire_core drm_kms_helper crc_itu_t syscopyarea sysfillrect ssb sysimgblt fb_sys_fops sky2 drm wmi fjes video
[ 2.084333] CPU: 1 PID: 6 Comm: kworker/u4:0 Tainted: G W 4.4.0-21-generic #37-Ubuntu
[ 2.084337] Hardware name: Dell Inc. Inspiron 1525 /0U990C, BIOS A17 10/27/2009
[ 2.084344] Workqueue: events_unbound async_run_entry_fn
[ 2.084348] 0000000000000286 00000000601d6afd ffff8800bb7f7938 ffffffff813e93c3
[ 2.084354] ffff8800bb7f7980 ffffffffc0058b10 ffff8800bb7f7970 ffffffff81080f62
[ 2.084360] ffff880035df3800 0000000000000000 0000000000000000 0000000000000005
[ 2.084365] Call Trace:
[ 2.084378] [<ffffffff813e93c3>] dump_stack+0x63/0x90
[ 2.084382] [<ffffffff81080f62>] warn_slowpath_common+0x82/0xc0
[ 2.084384] [<ffffffff81080ffc>] warn_slowpath_fmt+0x5c/0x80
[ 2.084388] [<ffffffff810c3575>] ? finish_wait+0x55/0x70
[ 2.084403] [<ffffffffc00292a5>] drm_wait_one_vblank+0x1b5/0x1c0 [drm]
[ 2.084406] [<ffffffff810c3a10>] ? wake_atomic_t_function+0x60/0x60
[ 2.084452] [<ffffffffc0202052>] intel_pre_disable_primary+0x52/0x80 [i915]
[ 2.084491] [<ffffffffc0202287>] intel_pre_plane_update+0x107/0x140 [i915]
[ 2.084530] [<ffffffffc0202800>] intel_atomic_commit+0xf0/0x6f0 [i915]
[ 2.084549] [<ffffffffc004280e>] ? drm_atomic_check_only+0x18e/0x590 [drm]
[ 2.084569] [<ffffffffc0042cf0>] ? drm_atomic_set_fb_for_plane+0x20/0x90 [drm]
[ 2.084588] [<ffffffffc0042c47>] drm_atomic_commit+0x37/0x60 [drm]
[ 2.084626] [<ffffffffc0208460>] intel_release_load_detect_pipe+0x120/0x160 [i915]
[ 2.084666] [<ffffffffc0241aeb>] intel_tv_detect+0x33b/0x5f0 [i915]
[ 2.084677] [<ffffffffc00e7da5>] drm_helper_probe_single_connector_modes_merge_bits+0x235/0x4d0 [drm_kms_helper]
[ 2.084685] [<ffffffffc00e8053>] drm_helper_probe_single_connector_modes+0x13/0x20 [drm_kms_helper]
[ 2.084694] [<ffffffffc00f491e>] drm_fb_helper_initial_config+0xae/0x420 [drm_kms_helper]
[ 2.084733] [<ffffffffc02184bb>] intel_fbdev_initial_config+0x1b/0x20 [i915]
[ 2.084736] [<ffffffff810a2f28>] async_run_entry_fn+0x48/0x150
[ 2.084739] [<ffffffff81099ff2>] process_one_work+0x162/0x480
[ 2.084742] [<ffffffff8109a35b>] worker_thread+0x4b/0x4c0
[ 2.084745] [<ffffffff8109a310>] ? process_one_work+0x480/0x480
[ 2.084747] [<ffffffff810a0528>] kthread+0xd8/0xf0
[ 2.084750] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 2.084754] [<ffffffff8182488f>] ret_from_fork+0x3f/0x70
[ 2.084757] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 2.084759] ---[ end trace f06ce4fed187d577 ]---
[ 2.184216] ------------[ cut here ]------------
[ 2.184244] WARNING: CPU: 1 PID: 6 at /build/linux-Ay7j_C/linux-4.4.0/drivers/gpu/drm/drm_irq.c:1326 drm_wait_one_vblank+0x1b5/0x1c0 [drm]()
[ 2.184247] vblank wait timed out on crtc 0
[ 2.184249] Modules linked in: hid_generic usbhid hid i915 psmouse ahci i2c_algo_bit firewire_ohci libahci sdhci_pci pata_acpi sdhci firewire_core drm_kms_helper crc_itu_t syscopyarea sysfillrect ssb sysimgblt fb_sys_fops sky2 drm wmi fjes video
[ 2.184282] CPU: 1 PID: 6 Comm: kworker/u4:0 Tainted: G W 4.4.0-21-generic #37-Ubuntu
[ 2.184285] Hardware name: Dell Inc. Inspiron 1525 /0U990C, BIOS A17 10/27/2009
[ 2.184290] Workqueue: events_unbound async_run_entry_fn
[ 2.184294] 0000000000000286 00000000601d6afd ffff8800bb7f7958 ffffffff813e93c3
[ 2.184299] ffff8800bb7f79a0 ffffffffc0058b10 ffff8800bb7f7990 ffffffff81080f62
[ 2.184305] ffff880035df3800 0000000000000000 0000000000000000 0000000000000005
[ 2.184310] Call Trace:
[ 2.184316] [<ffffffff813e93c3>] dump_stack+0x63/0x90
[ 2.184320] [<ffffffff81080f62>] warn_slowpath_common+0x82/0xc0
[ 2.184325] [<ffffffff81080ffc>] warn_slowpath_fmt+0x5c/0x80
[ 2.184330] [<ffffffff810c3575>] ? finish_wait+0x55/0x70
[ 2.184354] [<ffffffffc00292a5>] drm_wait_one_vblank+0x1b5/0x1c0 [drm]
[ 2.184360] [<ffffffff810c3a10>] ? wake_atomic_t_function+0x60/0x60
[ 2.184409] [<ffffffffc01fcf9f>] i9xx_crtc_disable+0x3f/0x450 [i915]
[ 2.184447] [<ffffffffc01f4f8c>] ? intel_crtc_disable_planes+0xdc/0xf0 [i915]
[ 2.184486] [<ffffffffc0202820>] intel_atomic_commit+0x110/0x6f0 [i915]
[ 2.184506] [<ffffffffc004280e>] ? drm_atomic_check_only+0x18e/0x590 [drm]
[ 2.184525] [<ffffffffc0042cf0>] ? drm_atomic_set_fb_for_plane+0x20/0x90 [drm]
[ 2.184544] [<ffffffffc0042c47>] drm_atomic_commit+0x37/0x60 [drm]
[ 2.184582] [<ffffffffc0208460>] intel_release_load_detect_pipe+0x120/0x160 [i915]
[ 2.184622] [<ffffffffc0241aeb>] intel_tv_detect+0x33b/0x5f0 [i915]
[ 2.184631] [<ffffffffc00e7da5>] drm_helper_probe_single_connector_modes_merge_bits+0x235/0x4d0 [drm_kms_helper]
[ 2.184639] [<ffffffffc00e8053>] drm_helper_probe_single_connector_modes+0x13/0x20 [drm_kms_helper]
[ 2.184648] [<ffffffffc00f491e>] drm_fb_helper_initial_config+0xae/0x420 [drm_kms_helper]
[ 2.184686] [<ffffffffc02184bb>] intel_fbdev_initial_config+0x1b/0x20 [i915]
[ 2.184689] [<ffffffff810a2f28>] async_run_entry_fn+0x48/0x150
[ 2.184692] [<ffffffff81099ff2>] process_one_work+0x162/0x480
[ 2.184695] [<ffffffff8109a35b>] worker_thread+0x4b/0x4c0
[ 2.184698] [<ffffffff8109a310>] ? process_one_work+0x480/0x480
[ 2.184700] [<ffffffff810a0528>] kthread+0xd8/0xf0
[ 2.184703] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 2.184706] [<ffffffff8182488f>] ret_from_fork+0x3f/0x70
[ 2.184709] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
[ 2.184711] ---[ end trace f06ce4fed187d578 ]---