One or two kernel versions back, the display on Lenovo Thinkpad T440p laptop started to blank from time to time. This happened irreguarly and not so often but with my current kernel gentoo-sources-3.16.5, it happens even several times per minute, although it is still irregular. Syslog reports the following lines right at time when display blanks: Dec 18 10:20:11 localhost kernel: [247803.660205] ------------[ cut here ]------------ Dec 18 10:20:11 localhost kernel: [247803.660224] WARNING: CPU: 2 PID: 2909 at drivers/gpu/drm/i915/intel_display.c:7256 hsw_enable_pc8+0x465/0x5e0() Dec 18 10:20:11 localhost kernel: [247803.660228] CRTC for pipe A enabled Dec 18 10:20:11 localhost kernel: [247803.660231] Modules linked in: tun nfnetlink_queue veth rfcomm ctr ccm act_police cls_basic cls_flow cls_fw cls_u32 sch_fq_codel sch_tbf sch_prio sch_htb sch_hfsc sch_ingress sch_sfq arptable_filter arp_tables bridge stp dm_thin_pool dm_persistent_data dm_bio_prison xt_CHECKSUM ipt_rpfilter xt_statistic xt_CT xt_LOG xt_connlimit xt_realm xt_addrtype xt_comment xt_recent xt_nat ipt_ULOG ipt_REJECT ipt_MASQUERADE ipt_ECN ipt_CLUSTERIP ipt_ah xt_set ip_set nf_nat_tftp nf_nat_snmp_basic nf_conntrack_snmp nf_nat_sip nf_nat_pptp nf_nat_proto_gre nf_nat_irc nf_nat_h323 nf_nat_ftp nf_nat_amanda ts_kmp nf_conntrack_amanda nf_conntrack_sane nf_conntrack_tftp nf_conntrack_sip nf_conntrack_proto_udplite nf_conntrack_proto_sctp nf_conntrack_pptp nf_conntrack_proto_gre nf_conntrack_netlink nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_irc nf_conntrack_h323 nf_conntrack_ftp xt_TPROXY xt_time xt_TCPMSS xt_tcpmss xt_sctp xt_policy xt_pkttype xt_physdev xt_owner xt_NFQUEUE xt_NFLOG nfnetlink_log xt_multiport xt_mark xt_mac xt_limit xt_length xt_iprange xt_helper xt_hashlimit xt_DSCP xt_dscp xt_dccp xt_conntrack xt_connmark xt_CLASSIFY xt_AUDIT xt_state iptable_raw iptable_nat nf_nat_ipv4 nf_nat iptable_mangle nfnetlink iptable_filter ip_tables bnep iwlmvm mac80211 iwlwifi x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel cfg80211 kvm uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core rtsx_pci_sdmmc v4l2_common mmc_core videodev rtsx_pci_ms snd_hda_codec_realtek memstick iTCO_wdt ecb snd_hda_codec_hdmi snd_hda_codec_generic iTCO_vendor_support media btusb crct10dif_pclmul rtsx_pci bluetooth crc32_pclmul crc32c_intel aesni_intel lrw snd_hda_intel glue_helper snd_hda_controller ablk_helper cryptd snd_hda_codec snd_hwdep shpchp pcspkr joydev e1000e thinkpad_acpi rfkill serio_raw lpc_ich wmi intel_smartconnect virtio_pci virtio_scsi virtio_blk virtio_net virtio_console virtio_balloon virtio_ring virtio xts gf128mul aes_x86_64 sha512_generic iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi e1000 fuse xfs libcrc32c jfs reiserfs btrfs multipath linear raid0 dm_raid raid456 async_raid6_recov async_memcpy raid1 raid10 async_pq async_xor xor async_tx raid6_pq dm_snapshot dm_bufio dm_crypt dm_mirror dm_region_hash dm_log firewire_core crc_itu_t hid_sunplus hid_sony led_class hid_samsung hid_pl hid_petalynx sl811_hcd usbhid ohci_pci uhci_hcd mpt2sas raid_class aic94xx libsas lpfc qla2xxx megaraid_sas megaraid aacraid sx8 DAC960 hpsa cciss 3w_9xxx 3w_xxxx mptsas scsi_transport_sas mptfc scsi_transport_fc mptspi mptscsih mptbase atp870u dc395x qla1280 imm parport dmx3191d sym53c8xx gdth advansys initio BusLogic arcmsr aic7xxx aic79xx pdc_adma sata_inic162x sata_mv sata_qstor sata_vsc sata_uli sata_sis sata_sx4 sata_nv sata_via sata_svw sata_sil24 sata_sil sata_promise pata_sl82c105 pata_via pata_jmicron pata_marvell pata_sis pata_netcell pata_pdc202xx_old pata_triflex pata_atiixp pata_opti pata_ali pata_it8213 pata_pcmcia pata_ns87415 pata_ns87410 pata_serverworks pata_cypress pata_artop pata_it821x pata_optidma pata_hpt3x2n pata_hpt3x3 pata_hpt37x pata_hpt366 pata_cmd64x pata_efar pata_rz1000 pata_sil680 pata_radisys pata_pdc2027x pata_mpiix xhci_hcd Dec 18 10:20:11 localhost kernel: [247803.660715] CPU: 2 PID: 2909 Comm: kworker/2:1 Tainted: G W O 3.16.5-gentoo #1 ... Dec 18 10:20:38 localhost kernel: [247830.561990] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off Additional information: - relevant package versions and USE flags: equery u gentoo-sources [ Legend : U - final flag setting for installation] [ : I - package is installed with flag ] [ Colors : set, unset ] * Found these USE flags for sys-kernel/gentoo-sources-3.16.5: U I - - build : !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1] - - deblob : Remove binary blobs from kernel sources to provide libre license compliance. - - experimental : Apply experimental patches; for more information, see "https://wiki.gentoo.org/wiki/Project:Kernel/Experimental". - - symlink : Force kernel ebuilds to automatically update the /usr/src/linux symlink equery u xorg-server [ Legend : U - final flag setting for installation] [ : I - package is installed with flag ] [ Colors : set, unset ] * Found these USE flags for x11-base/xorg-server-1.15.0: U I + + dmx : Build the Distributed Multiheaded X server - - doc : Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally + + ipv6 : Add support for IP version 6 + + kdrive : Build the kdrive X servers - - minimal : Install a very minimal build (disables, for example, plugins, fonts, most drivers, non-critical features) + + nptl : Enable support for Native POSIX Threads Library, the new threading module (requires linux-2.6 or better usually) - - static-libs : Build static versions of dynamic libraries as well + + suid : Enable setuid root program, with potential security risks - - tslib : Build with tslib support for touchscreen devices + + udev : Enable virtual/udev integration (device discovery, power and storage device support, etc) + + unwind : Enable libunwind usage for backtraces + + xnest : Build the Xnest server + + xorg : Build the Xorg X server (HIGHLY RECOMMENDED) + + xvfb : Build the Xvfb server equery u xorg-drivers [ Legend : U - final flag setting for installation] [ : I - package is installed with flag ] [ Colors : set, unset ] * Found these USE flags for x11-base/xorg-drivers-1.15: U I - - input_devices_acecad : INPUT_DEVICES setting to build driver for acecad input devices - - input_devices_aiptek : INPUT_DEVICES setting to build driver for aiptek input devices - - input_devices_elographics : INPUT_DEVICES setting to build driver for elographics input devices + + input_devices_evdev : INPUT_DEVICES setting to build driver for evdev input devices - - input_devices_fpit : INPUT_DEVICES setting to build driver for fpit input devices - - input_devices_hyperpen : INPUT_DEVICES setting to build driver for hyperpen input devices + + input_devices_joystick : INPUT_DEVICES setting to build driver for joystick input devices + + input_devices_keyboard : INPUT_DEVICES setting to build driver for keyboard input devices + + input_devices_mouse : INPUT_DEVICES setting to build driver for mouse input devices + + input_devices_mutouch : INPUT_DEVICES setting to build driver for mutouch input devices + + input_devices_penmount : INPUT_DEVICES setting to build driver for penmount input devices + + input_devices_synaptics : INPUT_DEVICES setting to build driver for synaptics input devices - - input_devices_tslib : INPUT_DEVICES setting to build driver for tslib input devices - - input_devices_vmmouse : INPUT_DEVICES setting to build driver for vmmouse input devices - - input_devices_void : INPUT_DEVICES setting to build driver for void/dummy input devices - - input_devices_wacom : INPUT_DEVICES setting to build driver for wacom input devices - - video_cards_apm : VIDEO_CARDS setting to build driver for apm video cards - - video_cards_ast : VIDEO_CARDS setting to build driver for ASpeedTech video cards - - video_cards_chips : VIDEO_CARDS setting to build driver for chips video cards - - video_cards_cirrus : VIDEO_CARDS setting to build driver for cirrus video cards - - video_cards_dummy : VIDEO_CARDS setting to build driver for dummy video cards - - video_cards_epson : VIDEO_CARDS setting to build driver for epson video cards - - video_cards_fbdev : VIDEO_CARDS setting to build driver for fbdev video cards - - video_cards_fglrx : VIDEO_CARDS setting to build driver for fglrx video cards - - video_cards_glint : VIDEO_CARDS setting to build driver for glint video cards - - video_cards_i128 : VIDEO_CARDS setting to build driver for Number 9 I128 video cards + + video_cards_intel : VIDEO_CARDS setting to build driver for Intel video cards - - video_cards_mach64 : VIDEO_CARDS setting to build driver for mach64 video cards - - video_cards_mga : VIDEO_CARDS setting to build driver for mga video cards - - video_cards_modesetting : VIDEO_CARDS setting to build driver for unaccelerated modesetting - - video_cards_neomagic : VIDEO_CARDS setting to build driver for neomagic video cards - - video_cards_nouveau : VIDEO_CARDS setting to build reverse-engineered driver for nvidia cards - - video_cards_nv : VIDEO_CARDS setting to build driver for nv video cards - - video_cards_nvidia : VIDEO_CARDS setting to build driver for nvidia video cards - - video_cards_qxl : VIDEO_CARDS setting to build driver for qxl (QEMU virtual GPU) - - video_cards_r128 : VIDEO_CARDS setting to build driver for ATI r128 video cards - - video_cards_radeon : VIDEO_CARDS setting to build driver for ATI radeon video cards - - video_cards_radeonsi : VIDEO_CARDS setting to build only Southern Islands based chips code for radeon - - video_cards_rendition : VIDEO_CARDS setting to build driver for rendition video cards - - video_cards_s3virge : VIDEO_CARDS setting to build driver for s3virge video cards - - video_cards_savage : VIDEO_CARDS setting to build driver for savage video cards - - video_cards_siliconmotion : VIDEO_CARDS setting to build driver for siliconmotion video cards - - video_cards_sisusb : VIDEO_CARDS setting to build driver for SiS USB video cards - - video_cards_tdfx : VIDEO_CARDS setting to build driver for tdfx video cards - - video_cards_tga : VIDEO_CARDS setting to build driver for tga video cards - - video_cards_trident : VIDEO_CARDS setting to build driver for trident video cards - - video_cards_tseng : VIDEO_CARDS setting to build driver for tseng video cards - - video_cards_v4l : VIDEO_CARDS setting to build driver for v4l video cards + + video_cards_vesa : VIDEO_CARDS setting to build driver for vesa video cards - - video_cards_via : VIDEO_CARDS setting to build driver for via video cards - - video_cards_virtualbox : VIDEO_CARDS setting to build driver for virtualbox emulation - - video_cards_vmware : VIDEO_CARDS setting to build driver for vmware video cards equery u genkernel-next [ Legend : U - final flag setting for installation] [ : I - package is installed with flag ] [ Colors : set, unset ] * Found these USE flags for sys-kernel/genkernel-next-55: U I + + cryptsetup : Enable support for Luks disk enrcyption using sys-fs/cryptsetup + + dmraid : Enable support for DMRAID (include dmraid dependency) + + gpg : Enable support for GPG (include gnupg dependency) + + iscsi : Enable support for open-iscsi (include open-iscsi dependency) + + plymouth : Enable support for Plymouth (include Plymouth dependency) Reproducible: Sometimes Steps to Reproduce: 1. Build the kernel using attached .config with initramfs using genkernel 2. Use it together with gdm-3.12.2, xorg-server-1.15.0 and xorg-drivers-1.15 for several days Actual Results: Screen occasionally blanks for few seconds and prints huge WARNING to syslog. Expected Results: Screen in X.Org sohuld not blank. I am not sure about severity I selected - I feel that it should be critical since such warnings should not happen and the main functionality - displaying graphics is broken for some time. Despite that it happens only for few seconds, it is truly annoying. Please revise the severity and correct if needed.
Created attachment 391960 [details] Relevant portion of syslog
Created attachment 391962 [details] Kernel .config
Created attachment 391964 [details] emerge --info output
Please try the latest kernel which is 3.18.1 as of this writing.
I will try that for few days to see if that happens again.
During the two previous weeks of using the new kernel version, I have not seen any problem. I propose to close the bug as RESOLVED FIXED.
Thanks for reporting
