Comment 0 for bug 1413238

On 14.10, X has been causing me all kinds of problems. It seems to most often happen after the screenlock has been on. When coming back from being locked, sometimes the system is unresponsive, but I can cajole it back to life by repeatedly going to a VT-- once I see a login prompt, I can usually Ctrl+Alt+F7 and start using the computer again. I have seen it happen without the screen being locked too (yesterday I was typing into Google docs when it happened). Occasionally I see a core dump in /etc/X11/core. I've been looking out for kernel tracebacks and today found one:
[790942.538129] ------------[ cut here ]------------
[790942.538205] WARNING: CPU: 0 PID: 1902 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:3324 intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]()
[790942.538208] Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c overlayfs uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common snd_usb_audio videodev snd_usbmidi_lib media uas usb_storage aufs xt_CHECKSUM iptable_mangle ipt_MASQUERADE ctr ccm bridge stp llc bnep bluetooth 6lowpan_iphc nfsd auth_rpcgss nfs_acl binfmt_misc nfs lockd sunrpc fscache dm_crypt arc4 iwldvm mac80211 xt_nat iptable_nat nf_nat_ipv4 ip6t_REJECT xt_hl ip6t_rt dm_multipath intel_powerclamp nf_conntrack_ipv6 nf_defrag_ipv6 coretemp scsi_dh kvm_intel snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic xt_comment kvm crct10dif_pclmul crc32_pclmul ipt_REJECT ghash_clmulni_intel snd_hda_intel snd_hda_controller xt_LOG aesni_intel snd_hda_codec snd_hwdep xt_recent
[790942.538263] snd_pcm aes_x86_64 lrw gf128mul glue_helper snd_seq_midi snd_seq_midi_event ablk_helper cryptd xt_limit snd_rawmidi xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack ip6table_filter ip6_tables joydev snd_seq serio_raw nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack iptable_filter iwlwifi thinkpad_acpi snd_seq_device nvram ip_tables snd_timer x_tables cfg80211 snd lpc_ich parport_pc mac_hid soundcore ppdev mei_me shpchp mei lp parport nbd hid_logitech_dj hid_generic usbhid hid i915 psmouse ahci e1000e libahci ptp i2c_algo_bit pps_core drm_kms_helper drm video wmi [last unloaded: rfcomm]
[790942.538313] CPU: 0 PID: 1902 Comm: Xorg Tainted: G W 3.16.0-28-generic #38-Ubuntu
[790942.538316] Hardware name: LENOVO 5129CTO/5129CTO, BIOS 6QET64WW (1.34 ) 02/24/2011
[790942.538318] 0000000000000009 ffff8800b59b7be0 ffffffff81781eaa 0000000000000000
[790942.538322] ffff8800b59b7c18 ffffffff8106fedd 0000000000000000 ffff88022c576000
[790942.538325] ffff88022c238210 ffff880035d29800 ffff880035d29800 ffff8800b59b7c28
[790942.538329] Call Trace:
[790942.538341] [<ffffffff81781eaa>] dump_stack+0x45/0x56
[790942.538348] [<ffffffff8106fedd>] warn_slowpath_common+0x7d/0xa0
[790942.538352] [<ffffffff8106ffba>] warn_slowpath_null+0x1a/0x20
[790942.538384] [<ffffffffc01e604c>] intel_crtc_wait_for_pending_flips+0x16c/0x180 [i915]
[790942.538390] [<ffffffff810b9710>] ? prepare_to_wait_event+0x100/0x100
[790942.538419] [<ffffffffc01e8b13>] intel_crtc_disable_planes+0x33/0x1c0 [i915]
[790942.538448] [<ffffffffc01e90e0>] ironlake_crtc_disable+0x50/0x980 [i915]
[790942.538476] [<ffffffffc01d3f4e>] ? gen5_write32+0x5e/0xc0 [i915]
[790942.538505] [<ffffffffc01ea4a7>] intel_crtc_update_dpms+0x67/0xa0 [i915]
[790942.538535] [<ffffffffc01fd7aa>] intel_crt_dpms+0x6a/0xb0 [i915]
[790942.538561] [<ffffffffc00a1cd9>] ? drm_mode_object_find+0x29/0x70 [drm]
[790942.538583] [<ffffffffc00a6e19>] drm_mode_obj_set_property_ioctl+0x399/0x3a0 [drm]
[790942.538605] [<ffffffffc00a6e50>] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm]
[790942.538620] [<ffffffffc0095a4f>] drm_ioctl+0x1df/0x680 [drm]
[790942.538628] [<ffffffff811f5138>] do_vfs_ioctl+0x2c8/0x4a0
[790942.538632] [<ffffffff81784b2d>] ? __schedule+0x39d/0x890
[790942.538636] [<ffffffff811f5391>] SyS_ioctl+0x81/0xa0
[790942.538641] [<ffffffff81789eed>] system_call_fastpath+0x1a/0x1f
[790942.538643] ---[ end trace e5ef63131e3903d7 ]---

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-image-3.16.0-28-generic 3.16.0-28.38
ProcVersionSignature: Ubuntu 3.16.0-28.38-generic 3.16.7-ckt1
Uname: Linux 3.16.0-28-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jamie 3479 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed Jan 21 08:42:16 2015
HibernationDevice: RESUME=UUID=c4c5dbc0-d41a-428d-8af4-b680b67dd3dc
InstallationDate: Installed on 2011-06-28 (1302 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110425.2)
MachineType: LENOVO 5129CTO
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-28-generic root=UUID=88689ad2-74b5-442c-9290-8ae60b63e16b ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-28-generic N/A
 linux-backports-modules-3.16.0-28-generic N/A
 linux-firmware 1.138.1
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to utopic on 2013-11-04 (442 days ago)
dmi.bios.date: 02/24/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 6QET64WW (1.34 )
dmi.board.name: 5129CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6QET64WW(1.34):bd02/24/2011:svnLENOVO:pn5129CTO:pvrThinkPadX201s:rvnLENOVO:rn5129CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 5129CTO
dmi.product.version: ThinkPad X201s
dmi.sys.vendor: LENOVO