4.2.0-27-generic #32-Ubuntu SMP Fri Jan 22 04:49:08 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

I have the same issue and it comes every 2-5 minutes

Jan 23 11:56:59 zhakal kernel: [  212.683811] WARNING: CPU: 6 PID: 1446 at /build/linux-NgsOGa/linux-4.2.0/drivers/gpu/drm/i915/intel_pm.c:3404 skl_update_other_pipe_wm+0x1de/0x1f0 [i915]()
Jan 23 11:56:59 zhakal kernel: [  212.683812] WARN_ON(!wm_changed)
Jan 23 11:56:59 zhakal kernel: [  212.683813] Modules linked in: ip6table_filter ip6_tables iptable_filter ip_tables x_tables pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) rpcsec_gss_krb5 nfsv4 nfsv3 nfs fscache joydev input_leds zram lz4_compress snd_hda_codec_hdmi uvcvideo snd_hda_codec_realtek videobuf2_vmalloc snd_hda_codec_generic videobuf2_memops videobuf2_core v4l2_common videodev snd_usb_audio media snd_usbmidi_lib snd_hda_intel hid_generic snd_hda_codec intel_rapl snd_hda_core x86_pkg_temp_thermal snd_hwdep intel_powerclamp snd_pcm coretemp eeepc_wmi asus_wmi sparse_keymap kvm snd_seq_midi snd_seq_midi_event snd_rawmidi crct10dif_pclmul crc32_pclmul snd_seq usbhid snd_seq_device aesni_intel snd_timer aes_x86_64 snd lrw gf128mul soundcore glue_helper ablk_helper cryptd serio_raw shpchp mei_me mei acpi_als kfifo_buf 8250_fintek intel_lpss_acpi intel_lpss industrialio mac_hid acpi_pad nfsd auth_rpcgss nfs_acl lockd grace sunrpc parport_pc ppdev lp parport autofs4 mxm_wmi i915 e1000e i2c_algo_bit psmouse drm_kms_helper ptp pps_core drm ahci libahci wmi video pinctrl_sunrisepoint i2c_hid pinctrl_intel hid
Jan 23 11:56:59 zhakal kernel: [  212.683869] CPU: 6 PID: 1446 Comm: Xorg Tainted: G        W  OE   4.2.0-27-generic #32-Ubuntu
Jan 23 11:56:59 zhakal kernel: [  212.683870] Hardware name: System manufacturer System Product Name/Z170 PRO GAMING, BIOS 1202 12/25/2015
Jan 23 11:56:59 zhakal kernel: [  212.683871]  0000000000000000 00000000138afa90 ffff880425d6b518 ffffffff817eae99
Jan 23 11:56:59 zhakal kernel: [  212.683872]  0000000000000000 ffff880425d6b570 ffff880425d6b558 ffffffff8107b9c6
Jan 23 11:56:59 zhakal kernel: [  212.683874]  ffff880425d6b620 ffff880425d6b6c4 ffff880422d63000 ffff880422d62000
Jan 23 11:56:59 zhakal kernel: [  212.683875] Call Trace:
Jan 23 11:56:59 zhakal kernel: [  212.683881]  [<ffffffff817eae99>] dump_stack+0x45/0x57
Jan 23 11:56:59 zhakal kernel: [  212.683885]  [<ffffffff8107b9c6>] warn_slowpath_common+0x86/0xc0
Jan 23 11:56:59 zhakal kernel: [  212.683886]  [<ffffffff8107ba55>] warn_slowpath_fmt+0x55/0x70
Jan 23 11:56:59 zhakal kernel: [  212.683893]  [<ffffffffc01b8b9e>] skl_update_other_pipe_wm+0x1de/0x1f0 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683898]  [<ffffffffc01b8d6b>] skl_update_wm+0x1bb/0x740 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683913]  [<ffffffffc02048d7>] ? gen9_read32+0xf7/0x2d0 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683920]  [<ffffffffc01ed342>] ? i915_get_vblank_timestamp+0x62/0xa0 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683927]  [<ffffffffc01bc4be>] intel_update_watermarks+0x1e/0x30 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683938]  [<ffffffffc021fb79>] intel_finish_crtc_commit+0x169/0x190 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683945]  [<ffffffffc0114793>] drm_atomic_helper_commit_planes_on_crtc+0x143/0x260 [drm_kms_helper]
Jan 23 11:56:59 zhakal kernel: [  212.683956]  [<ffffffffc0238edb>] intel_atomic_commit+0x6b/0x100 [i915]
Jan 23 11:56:59 zhakal kernel: [  212.683977]  [<ffffffffc009bd47>] drm_atomic_commit+0x37/0x60 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.683980]  [<ffffffffc01130cf>] drm_atomic_helper_disable_plane+0xef/0x130 [drm_kms_helper]
Jan 23 11:56:59 zhakal kernel: [  212.683986]  [<ffffffffc008b93a>] __setplane_internal+0x23a/0x2f0 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.683991]  [<ffffffffc008bb1b>] drm_mode_cursor_universal+0x12b/0x210 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.683993]  [<ffffffff817ef9cf>] ? __ww_mutex_lock+0x5f/0xa0
Jan 23 11:56:59 zhakal kernel: [  212.683997]  [<ffffffffc008bc81>] drm_mode_cursor_common+0x81/0x180 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.684005]  [<ffffffffc008fca0>] drm_mode_cursor_ioctl+0x50/0x70 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.684009]  [<ffffffffc0080495>] drm_ioctl+0x125/0x610 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.684014]  [<ffffffffc008fc50>] ? drm_mode_setcrtc+0x500/0x500 [drm]
Jan 23 11:56:59 zhakal kernel: [  212.684018]  [<ffffffff812110b5>] do_vfs_ioctl+0x295/0x480
Jan 23 11:56:59 zhakal kernel: [  212.684020]  [<ffffffff811fd2d8>] ? __vfs_read+0x18/0x40
Jan 23 11:56:59 zhakal kernel: [  212.684021]  [<ffffffff811fd8a7>] ? vfs_read+0x87/0x130
Jan 23 11:56:59 zhakal kernel: [  212.684023]  [<ffffffff81211319>] SyS_ioctl+0x79/0x90
Jan 23 11:56:59 zhakal kernel: [  212.684024]  [<ffffffff817f1c72>] entry_SYSCALL_64_fastpath+0x16/0x75
Jan 23 11:56:59 zhakal kernel: [  212.684025] ---[ end trace 42acdfd8c91b2799 ]---
Jan 23 11:57:31 zhakal kernel: [  244.265189] ------------[ cut here ]------------