Bug 195585

After creating a second x-server or logging out of the x-server at least once the computr hangs for many seconds on every cntl+alt+fx switch or when switching window from/to firefox. 
> 
This problem exists at least in 4.9.16, 4.9.24, 4.10.12. 
Last kernel tested without that problem is 4.9.6. 

> dmesg-output:
[  425.322599] traps: ck-remove-direc[4471] trap int3 ip:7fc805f5a121 sp:7fff152b68f0 error:0
[  425.322608]  in libglib-2.0.so.0.5000.3[7fc805f0a000+112000]
[  434.036661] ------------[ cut here ]------------
[  434.036722] WARNING: CPU: 0 PID: 4477 at drivers/gpu/drm/i915/intel_display.c:14190 intel_atomic_commit_tail+0xfd7/0xfe0 [i915]
[  434.036724] pipe A vblank wait timed out
[  434.036760] Modules linked in: udlfb udl cdc_ncm usbnet snd_usb_audio snd_usbmidi_lib snd_rawmidi mii x86_pkg_temp_thermal iwldvm mac80211 kvm_intel snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic i915 i2c_algo_bit drm_kms_helper drm thinkpad_acpi kvm irqbypass snd_hda_intel snd_hda_codec pcspkr iwlwifi syscopyarea sysfillrect sysimgblt fb_sys_fops snd_hwdep intel_gtt mei_me lpc_ich mei snd_hda_core agpgart mfd_core
[  434.036766] CPU: 0 PID: 4477 Comm: X Not tainted 4.9.16-gentoo #2
[  434.036767] Hardware name: LENOVO 4180CE9/4180CE9, BIOS 83ET76WW (1.46 ) 07/05/2013
[  434.036775]  ffffb00d03e4f850 ffffffffb356b008 ffffb00d03e4f8a0 0000000000000000
[  434.036778]  ffffb00d03e4f890 ffffffffb328566c 0000376e00000000 0000000000000000
[  434.036782]  0000000000000000 0000000000000000 0000000000000001 ffff964f147cc000
[  434.036783] Call Trace:
[  434.036796]  [<ffffffffb356b008>] dump_stack+0x4d/0x65
[  434.036803]  [<ffffffffb328566c>] __warn+0xcc/0xf0
[  434.036808]  [<ffffffffb32856da>] warn_slowpath_fmt+0x4a/0x50
[  434.036817]  [<ffffffffb32c0831>] ? finish_wait+0x51/0x60
[  434.036857]  [<ffffffffc06ab247>] intel_atomic_commit_tail+0xfd7/0xfe0 [i915]
[  434.036897]  [<ffffffffc06b24e4>] ? intel_prepare_plane_fb+0x144/0x290 [i915]
[  434.036903]  [<ffffffffb32c09a0>] ? wake_up_atomic_t+0x30/0x30
[  434.036938]  [<ffffffffc06ab5a4>] intel_atomic_commit+0x354/0x4b0 [i915]
[  434.036957]  [<ffffffffc05c0ba2>] ? drm_atomic_add_affected_connectors+0x52/0xf0 [drm]
[  434.036970]  [<ffffffffc05c0734>] drm_atomic_commit+0x44/0x50 [drm]
[  434.036982]  [<ffffffffc0610bc7>] restore_fbdev_mode+0x147/0x260 [drm_kms_helper]
[  434.036990]  [<ffffffffc061277e>] drm_fb_helper_restore_fbdev_mode_unlocked+0x2e/0x70 [drm_kms_helper]
[  434.036998]  [<ffffffffc06127e8>] drm_fb_helper_set_par+0x28/0x50 [drm_kms_helper]
[  434.037036]  [<ffffffffc06c4c73>] intel_fbdev_set_par+0x13/0x70 [i915]
[  434.037042]  [<ffffffffb35f8e8f>] fb_set_var+0x19f/0x3e0
[  434.037048]  [<ffffffffb32aba04>] ? check_preempt_curr+0x74/0x80
[  434.037051]  [<ffffffffb32b2717>] ? update_curr+0xa7/0x130
[  434.037056]  [<ffffffffb35f567a>] fbcon_blank+0x20a/0x2e0
[  434.037062]  [<ffffffffb35d4b05>] do_unblank_screen+0xb5/0x1c0
[  434.037067]  [<ffffffffb35cb3f4>] complete_change_console+0x54/0xd0
[  434.037071]  [<ffffffffb35cc567>] vt_ioctl+0x10f7/0x12c0
[  434.037085]  [<ffffffffc05acac0>] ? drm_ioctl+0x210/0x4a0 [drm]
[  434.037096]  [<ffffffffc05a74d0>] ? drm_setmaster_ioctl+0x90/0x90 [drm]
[  434.037101]  [<ffffffffb35c08ba>] tty_ioctl+0x3ca/0xc20
[  434.037107]  [<ffffffffb33c247b>] do_vfs_ioctl+0x8b/0x5a0
[  434.037111]  [<ffffffffb33c2a04>] SyS_ioctl+0x74/0x80
[  434.037118]  [<ffffffffb39eaa20>] entry_SYSCALL_64_fastpath+0x13/0x94
[  434.037123] ---[ end trace 4b14721d5fa42134 ]---
[  444.202936] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  454.229220] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  463.988898] kworker/dying (29) used greatest stack depth: 12592 bytes left
[  464.255505] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  488.787879] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  502.654017] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  512.680300] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  522.919898] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  523.233222] ------------[ cut here ]------------
[  523.233283] WARNING: CPU: 3 PID: 4609 at drivers/gpu/drm/i915/intel_display.c:14190 intel_atomic_commit_tail+0xfd7/0xfe0 [i915]
[  523.233285] pipe A vblank wait timed out
[  523.233287] Modules linked in: udlfb udl cdc_ncm usbnet snd_usb_audio snd_usbmidi_lib snd_rawmidi mii x86_pkg_temp_thermal iwldvm mac80211 kvm_intel snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic i915 i2c_algo_bit drm_kms_helper drm thinkpad_acpi kvm irqbypass snd_hda_intel snd_hda_codec pcspkr iwlwifi syscopyarea sysfillrect sysimgblt fb_sys_fops snd_hwdep intel_gtt mei_me lpc_ich mei snd_hda_core agpgart mfd_core
[  523.233340] CPU: 3 PID: 4609 Comm: X Tainted: G        W       4.9.16-gentoo #2
[  523.233341] Hardware name: LENOVO 4180CE9/4180CE9, BIOS 83ET76WW (1.46 ) 07/05/2013
[  523.233346]  ffffb00d08cc3aa0 ffffffffb356b008 ffffb00d08cc3af0 0000000000000000
[  523.233352]  ffffb00d08cc3ae0 ffffffffb328566c 0000376e00000003 0000000000000000
[  523.233357]  0000000000000000 0000000000000000 0000000000000001 ffff964f147cc000
[  523.233362] Call Trace:
[  523.233375]  [<ffffffffb356b008>] dump_stack+0x4d/0x65
[  523.233382]  [<ffffffffb328566c>] __warn+0xcc/0xf0
[  523.233387]  [<ffffffffb32856da>] warn_slowpath_fmt+0x4a/0x50
[  523.233395]  [<ffffffffb32c0831>] ? finish_wait+0x51/0x60
[  523.233436]  [<ffffffffc06ab247>] intel_atomic_commit_tail+0xfd7/0xfe0 [i915]
[  523.233478]  [<ffffffffc06b24e4>] ? intel_prepare_plane_fb+0x144/0x290 [i915]
[  523.233484]  [<ffffffffb32c09a0>] ? wake_up_atomic_t+0x30/0x30
[  523.233519]  [<ffffffffc06ab5a4>] intel_atomic_commit+0x354/0x4b0 [i915]
[  523.233540]  [<ffffffffc05bfebb>] ? drm_atomic_set_crtc_for_connector+0xbb/0xf0 [drm]
[  523.233555]  [<ffffffffc05c0734>] drm_atomic_commit+0x44/0x50 [drm]
[  523.233567]  [<ffffffffc060f31c>] drm_atomic_helper_set_config+0x7c/0xb0 [drm_kms_helper]
[  523.233585]  [<ffffffffc05b3f60>] drm_mode_set_config_internal+0x60/0x110 [drm]
[  523.233600]  [<ffffffffc05b563c>] drm_mode_setcrtc+0x3bc/0x480 [drm]
[  523.233614]  [<ffffffffc05acaa1>] drm_ioctl+0x1f1/0x4a0 [drm]
[  523.233626]  [<ffffffffc05b5280>] ? drm_mode_getcrtc+0x140/0x140 [drm]
[  523.233633]  [<ffffffffb33c247b>] do_vfs_ioctl+0x8b/0x5a0
[  523.233637]  [<ffffffffb33c2a04>] SyS_ioctl+0x74/0x80
[  523.233644]  [<ffffffffb39eaa20>] entry_SYSCALL_64_fastpath+0x13/0x94
[  523.233649] ---[ end trace 4b14721d5fa42135 ]---
[  533.372840] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  547.290228] traps: ck-remove-direc[4661] trap int3 ip:7f32c31d3121 sp:7ffdd87a7e50 error:0
[  547.290238]  in libglib-2.0.so.0.5000.3[7f32c3183000+112000]
[  575.397915] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  699.553149] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  714.485931] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  768.883791] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out
[  782.963369] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out