Ok so I traced this to occuring after you install the nvidia driver. Using the intel card or the nouveau drivers the kernel log was clean. It was only after installing nvidia drivers (I tried various versions, from 367 up to 375) that I saw that in the kernel logs.
Either way, for me it does not seem to be actually affecting anything. My laptop (Precision 5510) is able to drive the external 4k monitor as well as its normal 4k screen. It's also able to push sound to the external 4k monitor (has built in speakers). So sound is working and so is the resolution. This error, while definitely concerning (and it definitely went away when I upgraded to the 4.8.x kernel), doesn't seem to actually affect me negatively. Additionally, I downgraded back to the original Ubuntu 14.04 based image Dell officially released the Precision 5510 with, to see if they'd custom patched the older kernel or anything, but they hadn't. Same error shows up in the kernel logs on the 14.04 distribution Dell included with the laptop. So they didn't see a need to fix it there either. -- 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/1567417 Title: WARN_ON(!wm_changed) skl_update_other_pipe_wm+0x16c/0x180 [i915_bpo] Status in linux package in Ubuntu: Confirmed Bug description: Hi, I'm using a new Skylake Thinkpad T460s with and external monitor connected via Displayport and Ubuntu 16.04 and the latest kernel as of today: Linux test 4.4.0-17-generic #33-Ubuntu SMP Tue Mar 29 17:17:28 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux X will from time to time lock up when the computer is left idle for a long time and both displays (laptop and external) go to sleep and then woken up. Apr 7 08:00:49 test kernel: [ 9.950929] ------------[ cut here ]------------ Apr 7 08:00:49 test kernel: [ 9.950950] WARNING: CPU: 0 PID: 214 at /build/linux-YiIlnA/linux-4.4.0/ubuntu/i915/intel_pm.c:3572 skl_update_other_pipe_wm+0x16c/0x180 [i915_bpo]() Apr 7 08:00:49 test kernel: [ 9.950951] WARN_ON(!wm_changed) Apr 7 08:00:49 test kernel: [ 9.950972] Modules linked in: btusb btrtl btbcm btintel bluetooth binfmt_misc nls_iso8859_1 arc4 snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine dw_dmac_core snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm thinkpad_acpi intel_rapl x86_pkg_temp_thermal nvram intel_powerclamp snd_seq_midi coretemp snd_seq_midi_event snd_rawmidi iwlmvm snd_seq joydev snd_seq_device input_leds mac80211 snd_timer serio_raw snd rtsx_pci_ms memstick soundcore iwlwifi cfg80211 mei_me mei tpm_crb mac_hid shpchp kvm_intel kvm irqbypass parport_pc ppdev lp parport autofs4 drbg ansi_cprng algif_skcipher af_alg hid_microsoft dm_crypt hid_generic usbhid hid rtsx_pci_sdmmc crct10dif_pclmul crc32_pclmul i915_bpo aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd intel_ips i2c_algo_bit drm_kms_helper e1000e syscop yarea sysfillrect psmouse sysimgblt ptp fb_sys_fops pps_core drm nvme rtsx_pci wmi video fjes Apr 7 08:00:49 test kernel: [ 9.950980] CPU: 0 PID: 214 Comm: plymouthd Not tainted 4.4.0-17-generic #33-Ubuntu Apr 7 08:00:49 test kernel: [ 9.950981] Hardware name: LENOVO 20F9CTO1WW/20F9CTO1WW, BIOS N1CET40W (1.08 ) 03/09/2016 Apr 7 08:00:49 test kernel: [ 9.950982] 0000000000000286 0000000039cb6999 ffff880502bc3618 ffffffff813e8123 Apr 7 08:00:49 test kernel: [ 9.950983] ffff880502bc3660 ffffffffc0343c70 ffff880502bc3650 ffffffff8107fe12 Apr 7 08:00:49 test kernel: [ 9.950984] ffff880502da8000 ffff880501f79d9c ffff880502dab000 ffff880508186b78 Apr 7 08:00:49 test kernel: [ 9.950984] Call Trace: Apr 7 08:00:49 test kernel: [ 9.950988] [<ffffffff813e8123>] dump_stack+0x63/0x90 Apr 7 08:00:49 test kernel: [ 9.950990] [<ffffffff8107fe12>] warn_slowpath_common+0x82/0xc0 Apr 7 08:00:49 test kernel: [ 9.950991] [<ffffffff8107feac>] warn_slowpath_fmt+0x5c/0x80 Apr 7 08:00:49 test kernel: [ 9.951002] [<ffffffffc02755cc>] skl_update_other_pipe_wm+0x16c/0x180 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951010] [<ffffffffc0275766>] skl_update_wm+0x186/0x5f0 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951023] [<ffffffffc03013af>] ? intel_ddi_enable_transcoder_func+0x17f/0x260 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951034] [<ffffffffc027948e>] intel_update_watermarks+0x1e/0x30 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951048] [<ffffffffc02e5441>] haswell_crtc_enable+0x321/0x8c0 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951061] [<ffffffffc02d1ace>] ? intel_finish_crtc_commit+0xe/0x10 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951072] [<ffffffffc017b324>] ? drm_atomic_helper_commit_planes_on_crtc+0x154/0x270 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951085] [<ffffffffc02e1ded>] intel_atomic_commit+0x5dd/0xdb0 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951101] [<ffffffffc007180e>] ? drm_atomic_check_only+0x18e/0x590 [drm] Apr 7 08:00:49 test kernel: [ 9.951109] [<ffffffffc0071c47>] drm_atomic_commit+0x37/0x60 [drm] Apr 7 08:00:49 test kernel: [ 9.951113] [<ffffffffc017c5ef>] restore_fbdev_mode+0x22f/0x260 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951121] [<ffffffffc007046a>] ? drm_modeset_lock_all_ctx+0x9a/0xb0 [drm] Apr 7 08:00:49 test kernel: [ 9.951125] [<ffffffffc017e7d3>] drm_fb_helper_restore_fbdev_mode_unlocked+0x33/0x80 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951128] [<ffffffffc017e84d>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951131] [<ffffffffc017e752>] drm_fb_helper_hotplug_event+0xd2/0x120 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951134] [<ffffffffc017e7f6>] drm_fb_helper_restore_fbdev_mode_unlocked+0x56/0x80 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951136] [<ffffffffc017e84d>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper] Apr 7 08:00:49 test kernel: [ 9.951150] [<ffffffffc02f79aa>] intel_fbdev_set_par+0x1a/0x60 [i915_bpo] Apr 7 08:00:49 test kernel: [ 9.951151] [<ffffffff8146b2b6>] fb_set_var+0x236/0x460 Apr 7 08:00:49 test kernel: [ 9.951153] [<ffffffff810b217d>] ? select_idle_sibling+0xbd/0x120 Apr 7 08:00:49 test kernel: [ 9.951155] [<ffffffff810b3441>] ? wakeup_preempt_entity.isra.55+0x41/0x50 Apr 7 08:00:49 test kernel: [ 9.951156] [<ffffffff810b3e8a>] ? check_preempt_wakeup+0xfa/0x220 Apr 7 08:00:49 test kernel: [ 9.951158] [<ffffffff814615af>] fbcon_blank+0x30f/0x350 Apr 7 08:00:49 test kernel: [ 9.951160] [<ffffffff814f85c3>] do_unblank_screen+0xd3/0x1a0 Apr 7 08:00:49 test kernel: [ 9.951161] [<ffffffff814edc4a>] vt_ioctl+0x50a/0x12f0 Apr 7 08:00:49 test kernel: [ 9.951167] [<ffffffffc0056749>] ? drm_ioctl+0x189/0x540 [drm] Apr 7 08:00:49 test kernel: [ 9.951168] [<ffffffff814e117f>] tty_ioctl+0x35f/0xc40 Apr 7 08:00:49 test kernel: [ 9.951170] [<ffffffff81821f79>] ? schedule_hrtimeout_range_clock+0xb9/0x1b0 Apr 7 08:00:49 test kernel: [ 9.951172] [<ffffffff812544eb>] ? ep_poll+0x37b/0x3d0 Apr 7 08:00:49 test kernel: [ 9.951173] [<ffffffff8121ef3f>] do_vfs_ioctl+0x29f/0x490 Apr 7 08:00:49 test kernel: [ 9.951175] [<ffffffff810aaca0>] ? wake_up_q+0x70/0x70 Apr 7 08:00:49 test kernel: [ 9.951176] [<ffffffff8121f1a9>] SyS_ioctl+0x79/0x90 Apr 7 08:00:49 test kernel: [ 9.951177] [<ffffffff81822b72>] entry_SYSCALL_64_fastpath+0x16/0x71 Apr 7 08:00:49 test kernel: [ 9.951178] ---[ end trace 7e448a85359a7dca ]--- Attached is the full kernel log from boot until the issue happens, at which point, if I have a lockup of X I need to reboot to get back to normal. I don't know if this particular bug I'm reporting is the one responsible for the lockups, as I've isolated 4 different warning/error messages which separately or in combination may be the cause. I'm reporting all of them now in separate bug reports. Please let me know if any information is missing. # lspci 00:00.0 Host bridge: Intel Corporation Sky Lake Host Bridge/DRAM Registers (rev 08) 00:02.0 VGA compatible controller: Intel Corporation Sky Lake Integrated Graphics (rev 07) 00:08.0 System peripheral: Intel Corporation Sky Lake Gaussian Mixture Model 00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21) 00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21) 00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI (rev 21) 00:1c.0 PCI bridge: Intel Corporation Device 9d10 (rev f1) 00:1c.2 PCI bridge: Intel Corporation Device 9d12 (rev f1) 00:1c.4 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port (rev f1) 00:1f.0 ISA bridge: Intel Corporation Sunrise Point-LP LPC Controller (rev 21) 00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21) 00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21) 00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21) 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection I219-LM (rev 21) 02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01) 04:00.0 Network controller: Intel Corporation Wireless 8260 (rev 3a) 05:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller (rev 01) # lspci -vvv 00:00.0 Host bridge: Intel Corporation Sky Lake Host Bridge/DRAM Registers (rev 08) Subsystem: Lenovo Skylake Host Bridge/DRAM Registers Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR- INTx- Latency: 0 Capabilities: [e0] Vendor Specific Information: Len=10 <?> 00:02.0 VGA compatible controller: Intel Corporation Sky Lake Integrated Graphics (rev 07) (prog-if 00 [VGA controller]) Subsystem: Lenovo Skylake Integrated Graphics Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 133 Region 0: Memory at f0000000 (64-bit, non-prefetchable) [size=16M] Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M] Region 4: I/O ports at e000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [40] Vendor Specific Information: Len=0c <?> Capabilities: [70] Express (v2) Root Complex Integrated Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0 ExtTag- RBE+ DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend- DevCap2: Completion Timeout: Not Supported, TimeoutDis-, LTR-, OBFF Not Supported DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee00018 Data: 0000 Capabilities: [d0] Power Management version 2 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [100 v1] #1b Capabilities: [200 v1] Address Translation Service (ATS) ATSCap: Invalidate Queue Depth: 00 ATSCtl: Enable-, Smallest Translation Unit: 00 Capabilities: [300 v1] #13 Kernel driver in use: i915_bpo Kernel modules: i915_bpo # for file in /sys/module/i915_bpo/parameters/*; do echo -en $file"\t"; cat $file; done; /sys/module/i915_bpo/parameters/disable_display N /sys/module/i915_bpo/parameters/disable_power_well 1 /sys/module/i915_bpo/parameters/edp_vswing 0 /sys/module/i915_bpo/parameters/enable_cmd_parser 1 /sys/module/i915_bpo/parameters/enable_dc -1 /sys/module/i915_bpo/parameters/enable_execlists 1 /sys/module/i915_bpo/parameters/enable_fbc -1 /sys/module/i915_bpo/parameters/enable_guc_submission N /sys/module/i915_bpo/parameters/enable_hangcheck Y /sys/module/i915_bpo/parameters/enable_ips 1 /sys/module/i915_bpo/parameters/enable_ppgtt 3 /sys/module/i915_bpo/parameters/enable_psr 0 /sys/module/i915_bpo/parameters/enable_rc6 1 /sys/module/i915_bpo/parameters/fastboot N /sys/module/i915_bpo/parameters/guc_log_level -1 /sys/module/i915_bpo/parameters/invert_brightness 0 /sys/module/i915_bpo/parameters/load_detect_test N /sys/module/i915_bpo/parameters/lvds_channel_mode 0 /sys/module/i915_bpo/parameters/lvds_use_ssc -1 /sys/module/i915_bpo/parameters/mmio_debug 0 /sys/module/i915_bpo/parameters/modeset -1 /sys/module/i915_bpo/parameters/nuclear_pageflip N /sys/module/i915_bpo/parameters/panel_ignore_lid 1 /sys/module/i915_bpo/parameters/prefault_disable N /sys/module/i915_bpo/parameters/preliminary_hw_support 0 /sys/module/i915_bpo/parameters/reset Y /sys/module/i915_bpo/parameters/semaphores -1 /sys/module/i915_bpo/parameters/use_mmio_flip 0 /sys/module/i915_bpo/parameters/vbt_sdvo_panel_type -1 /sys/module/i915_bpo/parameters/verbose_state_checks Y --- ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 DistroRelease: Ubuntu 16.04 InstallationDate: Installed on 2016-04-03 (63 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160401) Package: linux (not installed) Tags: xenial Uname: Linux 4.6.0-040600rc7-generic x86_64 UnreportableReason: The running kernel is not an Ubuntu kernel UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1567417/+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
