I can confirm that this works for me on SKL, i5-6200U dell xps 13 9350. There used to be a crash at every boot and two on suspend, with external HDMI plugged in. I patched the drm-nightly kernel and compiled it manually.
-- 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/1523088 Title: WARN_ON(!wm_changed) warning and stacktrace in kernel log Status in X.Org X server: Confirmed Status in linux package in Ubuntu: Incomplete Bug description: I always get an warning and stacktrace (and it seems to hang a little bit). This occurs after reboot as well as when I move with the cursor between my hdmi monitor and my laptop. (This only occurs when HDMI is connected) Default Kubuntu install version 15.10 with kernel 4.2.0-19-generic Processor: i5 6300hq Graphics: gtx950m WARNING: CPU: 1 PID: 827 at /build/linux-26_gwp/linux-4.2.0/drivers/gpu/drm/i915/intel_pm.c:3404 skl_update_other_pipe_wm+0x1de/0x1f0 [i915]() [Sam Dez 5 12:34:46 2015] WARN_ON(!wm_changed) [Sam Dez 5 12:34:46 2015] Modules linked in: [Sam Dez 5 12:34:46 2015] nls_iso8859_1 pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) drbg ansi_cprng ctr ccm rfcomm bnep arc4 rtsx_usb_ms memstick i2c_designware_platform i2c_designware_core acer_wmi sparse_keymap snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core intel_rapl snd_hwdep iosf_mbi x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq crct10dif_pclmul crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul snd_seq_device glue_helper snd_timer ablk_helper cryptd ath10k_pci ath10k_core snd ath mac80211 serio_raw soundcore idma64 virt_dma cfg80211 joydev input_leds uvcvideo mei_me videobuf2_vmalloc videobuf2_memops mei videobuf2_core v4l2_common intel_lpss_pci videodev media [Sam Dez 5 12:34:46 2015] btusb btrtl btbcm btintel bluetooth shpchp dell_smo8800 intel_lpss_acpi intel_lpss tpm_crb acpi_pad mac_hid parport_pc ppdev lp parport autofs4 hid_generic hid_logitech_hidpp hid_logitech_dj usbhid rtsx_usb_sdmmc rtsx_usb uas usb_storage nouveau i915 mxm_wmi ttm i2c_algo_bit drm_kms_helper r8169 mii drm ahci libahci i2c_hid hid wmi pinctrl_sunrisepoint video pinctrl_intel [Sam Dez 5 12:34:46 2015] CPU: 1 PID: 827 Comm: Xorg Tainted: G W OE 4.2.0-19-generic #23-Ubuntu [Sam Dez 5 12:34:46 2015] Hardware name: Acer Aspire V5-591G/Usopp_SLS, BIOS V1.03 10/23/2015 [Sam Dez 5 12:34:46 2015] 0000000000000000 00000000a287b8f0 ffff880071b03518 ffffffff817e93f9 [Sam Dez 5 12:34:46 2015] 0000000000000000 ffff880071b03570 ffff880071b03558 ffffffff8107b3d6 [Sam Dez 5 12:34:46 2015] ffff880071b03620 ffff880071b036c4 ffff880279bf2000 ffff880279bf7000 [Sam Dez 5 12:34:46 2015] Call Trace: [Sam Dez 5 12:34:46 2015] [<ffffffff817e93f9>] dump_stack+0x45/0x57 [Sam Dez 5 12:34:46 2015] [<ffffffff8107b3d6>] warn_slowpath_common+0x86/0xc0 [Sam Dez 5 12:34:46 2015] [<ffffffff8107b465>] warn_slowpath_fmt+0x55/0x70 [Sam Dez 5 12:34:46 2015] [<ffffffffc017eb9e>] skl_update_other_pipe_wm+0x1de/0x1f0 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc017ed6b>] skl_update_wm+0x1bb/0x740 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc01ca837>] ? gen9_read32+0xf7/0x2d0 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc01b32a2>] ? i915_get_vblank_timestamp+0x62/0xa0 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc01824be>] intel_update_watermarks+0x1e/0x30 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc01e5ad9>] intel_finish_crtc_commit+0x169/0x190 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc00f3793>] drm_atomic_helper_commit_planes_on_crtc+0x143/0x260 [drm_kms_helper] [Sam Dez 5 12:34:46 2015] [<ffffffffc01fee3b>] intel_atomic_commit+0x6b/0x100 [i915] [Sam Dez 5 12:34:46 2015] [<ffffffffc0094d47>] drm_atomic_commit+0x37/0x60 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffffc00f20cf>] drm_atomic_helper_disable_plane+0xef/0x130 [drm_kms_helper] [Sam Dez 5 12:34:46 2015] [<ffffffffc008493a>] __setplane_internal+0x23a/0x2f0 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffffc0084b1b>] drm_mode_cursor_universal+0x12b/0x210 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffff817edf2f>] ? __ww_mutex_lock+0x5f/0xa0 [Sam Dez 5 12:34:46 2015] [<ffffffffc0084c81>] drm_mode_cursor_common+0x81/0x180 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffffc0088ca0>] drm_mode_cursor_ioctl+0x50/0x70 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffffc0079495>] drm_ioctl+0x125/0x610 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffffc0088c50>] ? drm_mode_setcrtc+0x500/0x500 [drm] [Sam Dez 5 12:34:46 2015] [<ffffffff81210a25>] do_vfs_ioctl+0x295/0x480 [Sam Dez 5 12:34:46 2015] [<ffffffff81087f71>] ? __set_task_blocked+0x41/0xa0 [Sam Dez 5 12:34:46 2015] [<ffffffff81210c89>] SyS_ioctl+0x79/0x90 [Sam Dez 5 12:34:46 2015] [<ffffffff817f01f2>] entry_SYSCALL_64_fastpath+0x16/0x75 [Sam Dez 5 12:34:46 2015] ---[ end trace c72c2dc92b88cd01 ]--- ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: xserver-xorg-core 2:1.17.2-1ubuntu9.1 ProcVersionSignature: Ubuntu 4.2.0-19.23-generic 4.2.6 Uname: Linux 4.2.0-19-generic x86_64 ApportVersion: 2.19.1-0ubuntu5 Architecture: amd64 Date: Sat Dec 5 12:35:24 2015 ExecutablePath: /usr/bin/Xorg InstallationDate: Installed on 2015-12-04 (0 days ago) InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) SourcePackage: xorg-server UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/xorg-server/+bug/1523088/+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