On my T440s, after a couple of days of uptime (and reportedly after at
least one suspend/resume cycle, but I do that all the time), the screen
goes blank at random (but increasingly more frequent it seems)
intervals. Sometimes it comes back by itself, but usually, some input
like touchpad movement is required. A reboot fixes it for a while, but
that is not really such a great workaround.
The following appears in syslog while this happens:
Mar 14 12:11:24 lightning kernel: [639889.002569] ------------[ cut here ]------------
Mar 14 12:11:24 lightning kernel: [639889.002580] WARNING: CPU: 1 PID: 11949 at /build/linux-y7bjb0/linux-3.16.7-ckt4/drivers/gpu/drm/i915/intel_display.c:7266 hsw_enable_pc8+0x575/0x5e0 [i915]()
Mar 14 12:11:24 lightning kernel: [639889.002582] PCH PWM1 enabled
Mar 14 12:11:24 lightning kernel: [639889.002583] Modules linked in: ctr ccm hid_generic usbhid hid binfmt_misc bnep nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc snd_hda_codec_hdmi
uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media snd_hda_codec_realtek snd_hda_codec_generic x86_pkg_temp_thermal arc4 joydev intel_powerclamp iwlmvm i915 intel
_rapl snd_hda_intel iTCO_wdt iTCO_vendor_support snd_hda_controller ecb snd_hda_codec btusb coretemp snd_hwdep mac80211 drm_kms_helper thinkpad_acpi kvm bluetooth drm nvram snd_pcm snd_timer rtsx_pc
i_ms memstick snd mei_me 6lowpan_iphc tpm_tis pcspkr psmouse evdev serio_raw iwlwifi cfg80211 soundcore tpm ac i2c_algo_bit battery wmi lpc_ich shpchp i2c_i801 i2c_core button video rfkill m
ei processor intel_smartconnect fuse parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd2 algif_skcipher af_alg dm_crypt dm_mod sg sd_mod crc_t10dif crct10dif_generic ehci_pci xhci_hcd ehci_hcd rtsx_pci_sdmmc mmc_core crct10dif_pclmul crct10dif_common crc32_pclmul crc32c_intel ghash_clmulni_intel ahci aesni_intel libahci aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd libata e1000e scsi_mod ptp pps_core rtsx_pci mfd_core usbcore thermal usb_common thermal_sys
Mar 14 12:11:24 lightning kernel: [639889.002664] CPU: 1 PID: 11949 Comm: kworker/1:3 Tainted: G W 3.16.0-4-amd64 #1 Debian 3.16.7-ckt4-3
Mar 14 12:11:24 lightning kernel: [639889.002666] Hardware name: LENOVO 20AQ005QUS/20AQ005QUS, BIOS GJET76WW (2.26 ) 05/12/2014
Mar 14 12:11:24 lightning kernel: [639889.002669] Workqueue: pm pm_runtime_work
Mar 14 12:11:24 lightning kernel: [639889.002671] 0000000000000009 ffffffff815096a7 ffff880005d93ca8 ffffffff810676f7
Mar 14 12:11:24 lightning kernel: [639889.002675] ffff8800c6830000 ffff880005d93cf8 ffff8800c69a9b70 ffff8801197a2098
Mar 14 12:11:24 lightning kernel: [639889.002678] 0000000000000000 ffffffff8106775c ffffffffa0762a63 ffff880000000018
Mar 14 12:11:24 lightning kernel: [639889.002682] Call Trace:
Mar 14 12:11:24 lightning kernel: [639889.002686] [<ffffffff815096a7>] ? dump_stack+0x41/0x51
Mar 14 12:11:24 lightning kernel: [639889.002691] [<ffffffff810676f7>] ? warn_slowpath_common+0x77/0x90
Mar 14 12:11:24 lightning kernel: [639889.002695] [<ffffffff8106775c>] ? warn_slowpath_fmt+0x4c/0x50
Mar 14 12:11:24 lightning kernel: [639889.002709] [<ffffffffa06f4604>] ? gen6_read32+0x64/0x120 [i915]
Mar 14 12:11:24 lightning kernel: [639889.002722] [<ffffffffa070b9d5>] ? hsw_enable_pc8+0x575/0x5e0 [i915]
Mar 14 12:11:24 lightning kernel: [639889.002732] [<ffffffffa06b7895>] ? intel_runtime_suspend+0x185/0x860 [i915]
Mar 14 12:11:24 lightning kernel: [639889.002737] [<ffffffff812e23b9>] ? pci_pm_runtime_suspend+0x59/0x120
Mar 14 12:11:24 lightning kernel: [639889.002741] [<ffffffff813a983c>] ? __rpm_callback+0x2c/0x80
Mar 14 12:11:24 lightning kernel: [639889.002745] [<ffffffff813a98af>] ? rpm_callback+0x1f/0x80
Mar 14 12:11:24 lightning kernel: [639889.002749] [<ffffffff813a9a17>] ? rpm_suspend+0x107/0x5f0
Mar 14 12:11:24 lightning kernel: [639889.002754] [<ffffffff813aaeb2>] ? pm_runtime_work+0x72/0xa0
Mar 14 12:11:24 lightning kernel: [639889.002757] [<ffffffff81081492>] ? process_one_work+0x172/0x420
Mar 14 12:11:24 lightning kernel: [639889.002761] [<ffffffff81081b25>] ? worker_thread+0x115/0x520
Mar 14 12:11:24 lightning kernel: [639889.002764] [<ffffffff81081a10>] ? rescuer_thread+0x2d0/0x2d0
Mar 14 12:11:24 lightning kernel: [639889.002768] [<ffffffff81087ddd>] ? kthread+0xbd/0xe0
Mar 14 12:11:24 lightning kernel: [639889.002773] [<ffffffff81087d20>] ? kthread_create_on_node+0x180/0x180
Mar 14 12:11:24 lightning kernel: [639889.002777] [<ffffffff8150f6bc>] ? ret_from_fork+0x7c/0xb0
Mar 14 12:11:24 lightning kernel: [639889.002781] [<ffffffff81087d20>] ? kthread_create_on_node+0x180/0x180
Mar 14 12:11:24 lightning kernel: [639889.002783] ---[ end trace f08542f1f60ede1c ]---
This appears to be upstream bugs #86000/#86105 the former of which is
RESOLVED, but unfortunately the fix seems to be "use drm-intel-nightly".
Michael