Bug 115551

Hi, we are getting a lot of reports of the ThinkPad models randomnly freezing. The screen is visible, but the mouse and keyboard do not respond. 

I'm seeing the following information in the logs:
Mar 28 14:56:14 hostname kernel: [   53.478256] [drm:gen8_irq_handler [i915_bpo]] *ERROR* The master control interrupt lied (SDE)!
Mar 28 14:56:14 hostname kernel: [   53.478291] [drm:gen8_irq_handler [i915_bpo]] *ERROR* The master control interrupt lied (SDE)!
Mar 28 14:56:14 hostname kernel: [   53.478416] [drm:gen8_irq_handler [i915_bpo]] *ERROR* The master control interrupt lied (SDE)!
Mar 28 14:56:14 hostname kernel: [   53.478576] [drm:gen8_irq_handler [i915_bpo]] *ERROR* The master control interrupt lied (SDE)!

The above message was linked to this bug: https://bugs.freedesktop.org/show_bug.cgi?id=92084 and it seems that it's a no-op? So that doesn't seem to be the issue. 

And a kernel oops:

[   81.541081] snd_hda_intel 0000:00:1b.0: IRQ timing workaround is activated for card #0. Suggest a bigger bdl_pos_adj.
[   82.045438] ------------[ cut here ]------------
[   82.045478] WARNING: CPU: 0 PID: 3993 at /build/linux-lts-vivid-plKvyb/linux-lts-vivid-3.19.0/ubuntu/i915/intel_uncore.c:620 hsw_unclaimed_reg_debug.isra.14+0x80/0xa0 [i915_bpo]()
[   82.045481] Unclaimed register detected before reading register 0x223a0
[   82.045482] Modules linked in: ctr ccm iptable_nat nf_nat_ipv4 pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) xt_recent ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_hl ip6t_rt ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_NFLOG nfnetlink_log nfnetlink xt_limit lenovowmi(OE) xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 bnep rfcomm xt_addrtype xt_owner arc4 btusb bluetooth iwlmvm mac80211 uvcvideo videobuf2_vmalloc videobuf2_memops iwlwifi dm_multipath rtsx_pci_ms videobuf2_core v4l2_common memstick cfg80211 xt_conntrack scsi_dh videodev media intel_rapl iosf_mbi nfsd x86_pkg_temp_thermal intel_powerclamp binfmt_misc auth_rpcgss nfs_acl ip6table_filter snd_hda_codec_hdmi nfs coretemp lockd grace sunrpc ip6_tables snd_hda_codec_realtek fscache snd_hda_codec_generic xt_state xt_helper nf_nat_tftp nf_conntrack_tftp nf_nat_irc nf_conntrack_irc nf_nat_ftp kvm nf_nat nf_conntrack_ftp nf_conntrack snd_hda_intel iptable_filter snd_hda_controller snd_hda_codec snd_hwdep ip_tables x_tables joydev serio_raw snd_pcm lpc_ich shpchp snd_seq_midi snd_seq_midi_event mei_me mei snd_rawmidi i915_bpo thinkpad_acpi nvram snd_seq snd_seq_device snd_timer snd intel_ips soundcore mac_hid drm_kms_helper drm i2c_algo_bit parport_pc ppdev lp parport btrfs xor raid6_pq dm_crypt dm_mirror dm_region_hash dm_log crct10dif_pclmul crc32_pclmul rtsx_pci_sdmmc aesni_intel aes_x86_64 lrw e1000e gf128mul glue_helper psmouse ablk_helper cryptd ptp ahci pps_core libahci rtsx_pci wmi video
[   82.045578] CPU: 0 PID: 3993 Comm: WorkerPool/3993 Tainted: G           OE  3.19.0-51-generic #58~14.04.1-Ubuntu
[   82.045579] Hardware name: LENOVO 20CLS18S00/20CLS18S00, BIOS N10ET33W (1.12 ) 04/06/2015
[   82.045581]  ffffffffc04f28e0 ffff88022dc03c88 ffffffff817afe47 0000000000000000
[   82.045584]  ffff88022dc03cd8 ffff88022dc03cc8 ffffffff81074c3a ffff88022dc13ef8
[   82.045586]  ffff8802200e0078 ffff8802200e0000 ffff8802200e0080 ffff8802200e0078
[   82.045590] Call Trace:
[   82.045591]  <IRQ>  [<ffffffff817afe47>] dump_stack+0x45/0x57
[   82.045603]  [<ffffffff81074c3a>] warn_slowpath_common+0x8a/0xc0
[   82.045605]  [<ffffffff81074cb6>] warn_slowpath_fmt+0x46/0x50
[   82.045626]  [<ffffffffc0472410>] hsw_unclaimed_reg_debug.isra.14+0x80/0xa0 [i915_bpo]
[   82.045642]  [<ffffffffc04743ff>] gen6_read32+0x5f/0x1c0 [i915_bpo]
[   82.045658]  [<ffffffffc04693d8>] intel_lrc_irq_handler+0x38/0x250 [i915_bpo]
[   82.045672]  [<ffffffffc04607c4>] gen8_gt_irq_handler+0x274/0x2b0 [i915_bpo]
[   82.045686]  [<ffffffffc046087f>] gen8_irq_handler+0x7f/0x5a0 [i915_bpo]
[   82.045690]  [<ffffffff814c535a>] ? add_interrupt_randomness+0x3a/0x1e0
[   82.045694]  [<ffffffff810cbf1e>] handle_irq_event_percpu+0x3e/0x1a0
[   82.045697]  [<ffffffff810cc0c1>] handle_irq_event+0x41/0x70
[   82.045700]  [<ffffffff810cf06f>] handle_edge_irq+0x7f/0x120
[   82.045703]  [<ffffffff81017622>] handle_irq+0x22/0x40
[   82.045706]  [<ffffffff817ba821>] do_IRQ+0x51/0xf0
[   82.045709]  [<ffffffff817b862d>] common_interrupt+0x6d/0x6d
[   82.045711]  <EOI>  [<ffffffff817b7958>] ? sysret_audit+0x17/0x21
[   82.045715] ---[ end trace 8c5d88b69a683499 ]---