I've been having more luck with the newer 4.7 and 4.8 kernels, and using a 4k monitor on the integrated DP connector mostly works okay at 60Hz.
Haven't really noticed any difference in stability with the xorg.conf.d/20-intel.conf settings in https://github.com/linuxenko /ubuntu-skylake-i915-video-fix. I also tried with `Option "DRI" "false"`. Currently running 4.8.0-040800rc5-generic together with yakkety linux- firmware 1.160: Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-=================================-=====================-=====================-======================================================================== ii linux-firmware 1.160 all Firmware for Linux kernel drivers ii linux-image-4.8.0-040800rc5-gener 4.8.0-040800rc5.20160 amd64 Linux kernel image for version 4.8.0 on 64 bit x86 SMP Still getting warnings in dmesg when connecting a DP monitor: [ ...] Linux version 4.8.0-040800rc5-generic (kernel@tangerine) (gcc version 6.2.0 20160830 (Ubuntu 6.2.0-2ubuntu11) ) #201609041832 SMP Sun Sep 4 22:34:01 UTC 2016 .... [ 330.453739] ------------[ cut here ]------------ [ 330.453793] WARNING: CPU: 0 PID: 5134 at /home/kernel/COD/linux/drivers/gpu/drm/drm_irq.c:1215 drm_wait_one_vblank+0x16b/0x1b0 [drm] [ 330.453796] vblank not available on crtc 0, ret=-22 [ 330.453798] Modules linked in: uas usb_storage hid_lenovo usbhid hid ctr ccm pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) rfcomm fuse ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack br_netfilter bridge stp llc bnep snd_hda_codec_hdmi ext4 jbd2 arc4 snd_hda_codec_realtek snd_hda_codec_generic iwlmvm mac80211 fscrypto intel_rapl mbcache x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass intel_cstate intel_rapl_perf joydev serio_raw iwlwifi cfg80211 rtsx_pci_ms memstick option usb_wwan usbserial btusb btrtl cdc_ether btbcm usbnet btintel mii bluetooth sg crc16 snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core snd_soc_sst_match [ 330.453921] snd_soc_core snd_compress snd_pcm_dmaengine snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm thinkpad_acpi nvram rfkill battery ac snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd evdev tpm_tis tpm_tis_core tpm soundcore mei_me mei shpchp intel_pch_thermal parport_pc ppdev lp parport autofs4 btrfs xor raid6_pq algif_skcipher af_alg dm_crypt dm_mod sd_mod rtsx_pci_sdmmc mmc_core crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd i915 psmouse xhci_pci rtsx_pci xhci_hcd mfd_core ahci i2c_algo_bit usbcore libahci drm_kms_helper e1000e syscopyarea libata usb_common sysfillrect sysimgblt fb_sys_fops ptp pps_core drm scsi_mod thermal wmi video fjes button [ 330.454049] CPU: 0 PID: 5134 Comm: Xorg Tainted: G W OE 4.8.0-040800rc5-generic #201609041832 [ 330.454052] Hardware name: LENOVO 20F6007RGE/20F6007RGE, BIOS R02ET48W (1.21 ) 06/01/2016 [ 330.454057] 0000000000000286 000000000d9272e2 ffffffffb2541064 ffff9487a2e239c8 [ 330.454068] 0000000000000000 ffffffffb227f6ee ffff9487c7f30000 ffff9487a2e23a20 [ 330.454076] ffff9487c85a1600 ffff9487c7f303d8 ffff9487c7f30000 0000000000000000 [ 330.454085] Call Trace: [ 330.454099] [<ffffffffb2541064>] ? dump_stack+0x5c/0x78 [ 330.454108] [<ffffffffb227f6ee>] ? __warn+0xbe/0xe0 [ 330.454117] [<ffffffffb227f76f>] ? warn_slowpath_fmt+0x5f/0x80 [ 330.454155] [<ffffffffc01b7156>] ? drm_vblank_get+0x76/0xc0 [drm] [ 330.454192] [<ffffffffc01b739b>] ? drm_wait_one_vblank+0x16b/0x1b0 [drm] [ 330.454286] [<ffffffffc04a1890>] ? chv_write32+0x3c0/0x3c0 [i915] [ 330.454344] [<ffffffffc0451a8d>] ? skl_wm_flush_pipe+0xcd/0x100 [i915] [ 330.454400] [<ffffffffc04527cb>] ? skl_update_wm+0x42b/0x6c0 [i915] [ 330.454493] [<ffffffffc04c46a8>] ? haswell_crtc_enable+0x798/0x860 [i915] [ 330.454584] [<ffffffffc04c071f>] ? intel_atomic_commit_tail+0x84f/0x10a0 [i915] [ 330.454671] [<ffffffffc04c9040>] ? intel_prepare_plane_fb+0x100/0x2b0 [i915] [ 330.454698] [<ffffffffc0313a42>] ? drm_atomic_helper_setup_commit+0x252/0x320 [drm_kms_helper] [ 330.454784] [<ffffffffc04c13b2>] ? intel_atomic_commit+0x442/0x560 [i915] [ 330.454843] [<ffffffffc01cff22>] ? drm_atomic_set_crtc_for_connector+0x92/0xf0 [drm] [ 330.454870] [<ffffffffc0314789>] ? drm_atomic_helper_set_config+0x79/0xb0 [drm_kms_helper] [ 330.454919] [<ffffffffc01be671>] ? drm_mode_set_config_internal+0x61/0x110 [drm] [ 330.454969] [<ffffffffc01c312b>] ? drm_mode_setcrtc+0x42b/0x560 [drm] [ 330.455004] [<ffffffffc01b5b3b>] ? drm_ioctl+0x2ab/0x460 [drm] [ 330.455051] [<ffffffffc01c2d00>] ? drm_mode_setplane+0x1c0/0x1c0 [drm] [ 330.455059] [<ffffffffb2424faf>] ? do_vfs_ioctl+0x9f/0x640 [ 330.455069] [<ffffffffb228c1f7>] ? recalc_sigpending+0x17/0x50 [ 330.455078] [<ffffffffb228cf8d>] ? __set_task_blocked+0x3d/0x90 [ 330.455083] [<ffffffffb24255c4>] ? SyS_ioctl+0x74/0x80 [ 330.455094] [<ffffffffb281eb76>] ? entry_SYSCALL_64_fastpath+0x1e/0xa8 [ 330.455099] ---[ end trace f3839ca74b0e45b3 ]--- [ 591.794245] [drm:gen8_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun However, using the DP connector on a ThinkPad Pro Dock fails miserably with the mainline 4.8-rc kernels. I did get the display working via the dock connector the first time, but not anymore with the latest 4.8-rc kernels :( dmesg after a suspend/resume cycle: thinkpad_acpi: docked into hotplug port replicator [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit usb 2-4: new SuperSpeed USB device number 12 using xhci_hcd usb 2-4: New USB device found, idVendor=17ef, idProduct=1012 usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 2-4: Product: Lenovo ThinkPad Dock usb 2-4: Manufacturer: LENOVO hub 2-4:1.0: USB hub found hub 2-4:1.0: 4 ports detected usb 1-4: new high-speed USB device number 72 using xhci_hcd [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit usb 1-4: New USB device found, idVendor=17ef, idProduct=1012 usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-4: Product: Lenovo ThinkPad Dock usb 1-4: Manufacturer: LENOVO hub 1-4:1.0: USB hub found hub 1-4:1.0: 4 ports detected thinkpad_acpi: EC reports that Thermal Table has changed usb 1-4.4: new high-speed USB device number 73 using xhci_hcd <warn> (ttyUSB4): port attributes not fully set <warn> (ttyUSB2): port attributes not fully set <warn> (ttyUSB3): port attributes not fully set <warn> (ttyUSB1): port attributes not fully set usb 1-4.4: New USB device found, idVendor=17ef, idProduct=1011 usb 1-4.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 1-4.4: Product: Lenovo ThinkPad Dock usb 1-4.4: Manufacturer: Lenovo usb 1-4.4: SerialNumber: Rev1.2 hub 1-4.4:1.0: USB hub found hub 1-4.4:1.0: 3 ports detected [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_dp_start_link_train [i915]] *ERROR* failed to train DP, aborting [drm:intel_dp_start_link_train [i915]] *ERROR* Timed out waiting for DP idle patterns [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout waiting for DDI BUF C idle bit [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many voltage retries, give up [drm:intel_dp_start_link_train [i915]] *ERROR* failed to train DP, aborting [drm:intel_dp_start_link_train [i915]] *ERROR* Timed out waiting for DP idle patterns This matches with: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1568573 dmesg after initial boot: syys 05 10:12:57 tehobari kernel: thinkpad_acpi: docked into hotplug port replicator syys 05 10:12:59 tehobari kernel: ------------[ cut here ]------------ syys 05 10:12:59 tehobari kernel: WARNING: CPU: 1 PID: 5134 at /home/kernel/COD/linux/drivers/gpu/drm/drm_irq.c:1215 drm_wait_one_vblank+0x16b/0x1b0 [drm] syys 05 10:12:59 tehobari kernel: vblank not available on crtc 0, ret=-22 syys 05 10:12:59 tehobari kernel: Modules linked in: ctr ccm pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) rfcomm fuse ipt_MASQUERADE nf_nat_ syys 05 10:12:59 tehobari kernel: snd_pcm_dmaengine snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm thinkpad_acpi nvram rfkill battery ac snd_seq_ syys 05 10:12:59 tehobari kernel: CPU: 1 PID: 5134 Comm: Xorg Tainted: G W OE 4.8.0-040800rc5-generic #201609041832 syys 05 10:12:59 tehobari kernel: Hardware name: LENOVO 20F6007RGE/20F6007RGE, BIOS R02ET48W (1.21 ) 06/01/2016 syys 05 10:12:59 tehobari kernel: 0000000000000286 000000000d9272e2 ffffffffb2541064 ffff9487a2e239c8 syys 05 10:12:59 tehobari kernel: 0000000000000000 ffffffffb227f6ee ffff9487c7f30000 ffff9487a2e23a20 syys 05 10:12:59 tehobari kernel: ffff9487c85a1600 ffff9487c7f303d8 ffff9487c7f30000 0000000000000000 syys 05 10:12:59 tehobari kernel: Call Trace: syys 05 10:12:59 tehobari kernel: [<ffffffffb2541064>] ? dump_stack+0x5c/0x78 syys 05 10:12:59 tehobari kernel: [<ffffffffb227f6ee>] ? __warn+0xbe/0xe0 syys 05 10:12:59 tehobari kernel: [<ffffffffb227f76f>] ? warn_slowpath_fmt+0x5f/0x80 syys 05 10:12:59 tehobari kernel: [<ffffffffc01b7156>] ? drm_vblank_get+0x76/0xc0 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc01b739b>] ? drm_wait_one_vblank+0x16b/0x1b0 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc04a1890>] ? chv_write32+0x3c0/0x3c0 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc0451a8d>] ? skl_wm_flush_pipe+0xcd/0x100 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc04527cb>] ? skl_update_wm+0x42b/0x6c0 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc04c46a8>] ? haswell_crtc_enable+0x798/0x860 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc04c071f>] ? intel_atomic_commit_tail+0x84f/0x10a0 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc04c9040>] ? intel_prepare_plane_fb+0x100/0x2b0 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc0313a42>] ? drm_atomic_helper_setup_commit+0x252/0x320 [drm_kms_helper] syys 05 10:12:59 tehobari kernel: [<ffffffffc04c13b2>] ? intel_atomic_commit+0x442/0x560 [i915] syys 05 10:12:59 tehobari kernel: [<ffffffffc01cff22>] ? drm_atomic_set_crtc_for_connector+0x92/0xf0 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc0314789>] ? drm_atomic_helper_set_config+0x79/0xb0 [drm_kms_helper] syys 05 10:12:59 tehobari kernel: [<ffffffffc01be671>] ? drm_mode_set_config_internal+0x61/0x110 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc01c312b>] ? drm_mode_setcrtc+0x42b/0x560 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc01b5b3b>] ? drm_ioctl+0x2ab/0x460 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffc01c2d00>] ? drm_mode_setplane+0x1c0/0x1c0 [drm] syys 05 10:12:59 tehobari kernel: [<ffffffffb2424faf>] ? do_vfs_ioctl+0x9f/0x640 syys 05 10:12:59 tehobari kernel: [<ffffffffb228c1f7>] ? recalc_sigpending+0x17/0x50 syys 05 10:12:59 tehobari kernel: [<ffffffffb228cf8d>] ? __set_task_blocked+0x3d/0x90 syys 05 10:12:59 tehobari kernel: [<ffffffffb24255c4>] ? SyS_ioctl+0x74/0x80 syys 05 10:12:59 tehobari kernel: [<ffffffffb281eb76>] ? entry_SYSCALL_64_fastpath+0x1e/0xa8 syys 05 10:12:59 tehobari kernel: ---[ end trace f3839ca74b0e45b1 ]--- syys 05 10:12:59 tehobari kernel: thinkpad_acpi: EC reports that Thermal Table has changed syys 05 10:12:59 tehobari kernel: [drm:intel_mst_pre_enable_dp [i915]] *ERROR* failed to allocate vcpi syys 05 10:12:59 tehobari kernel: [drm:intel_mst_enable_dp [i915]] *ERROR* Timed out waiting for ACT sent The reference to MST here makes me think this is probably a different bug.. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1597267 Title: ThinkPad X260 connecting external DisplayPort hangs system Status in linux package in Ubuntu: Triaged Bug description: Running Ubuntu 16.04 on a Lenovo ThinkPad X260 with Intel Skylake HD Graphics 520, connecting an external monitor to the DisplayPort connector causes the system to quickly hang. The system stops responding to network pings, cannot switch consoles, and needs a hard reboot. The external monitor does work when using a text console, and does not always hang in the LightDM login screen, but starting up a desktop session will always hang. This originally happened using a ThinkPad dock, and I tested it further using an external DP monitor. This happens on 4.4.0-28-generic as well as mainline 4.6.3-040603-generic and 4.7.0-040700rc5-generic; they all hang in a similar fashion. I have attached a journalctl log from running 4.7.0-040700rc5-generic and connecting the DP monitor while in a text console, before switching to the graphical console and logging in. The system hangs after a series of: kernel: WARNING: CPU: 3 PID: 2319 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_pm.c:3647 skl_update_other_pipe_wm+0x15d/0x170 [i915] kernel: WARNING: CPU: 3 PID: 4418 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_display.c:13957 skl_max_scale.part.108+0x69/0x70 [i915] kernel: [drm:gen8_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun The first warnings come immediately when connecting, and others when switching consoles and logging in. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-28-generic 4.4.0-28.47 ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13 Uname: Linux 4.4.0-28-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: terom 1903 F.... pulseaudio CurrentDesktop: Unity Date: Wed Jun 29 13:03:18 2016 InstallationDate: Installed on 2016-06-26 (2 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) MachineType: LENOVO 20F6007RGE ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-28-generic root=UUID=6636a3bb-262e-4ab2-ae81-d9388e3f7684 ro rootflags=subvol=@ quiet splash RelatedPackageVersions: linux-restricted-modules-4.4.0-28-generic N/A linux-backports-modules-4.4.0-28-generic N/A linux-firmware 1.157.1 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 06/01/2016 dmi.bios.vendor: LENOVO dmi.bios.version: R02ET48W (1.21 ) dmi.board.asset.tag: Not Available dmi.board.name: 20F6007RGE dmi.board.vendor: LENOVO dmi.board.version: SDK0J40705 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrR02ET48W(1.21):bd06/01/2016:svnLENOVO:pn20F6007RGE:pvrThinkPadX260:rvnLENOVO:rn20F6007RGE:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNone: dmi.product.name: 20F6007RGE dmi.product.version: ThinkPad X260 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1597267/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp