WARN_ON(!wm_changed) warning and stacktrace in kernel log

Created attachment 113297
dmesg

==System Environment==
--------------------------
Bios : V68
Regression: No. First test on this platform.
boot with DP or HDMI monitor
Non-working platforms: SKLY

==kernel==
--------------------------
-nightly: b4442ee4e150506cebeee72249efc566c5f14bbe (fails)
     drm-intel-nightly: 2015y-02m-06d-09h-25m-00s UTC integration manifest

==Bug detailed description==
-----------------------------
testdisplay -a cause Call Trace

Detail:
[ 1242.330637] ------------[ cut here ]------------
[ 1242.330681] WARNING: CPU: 0 PID: 1361 at drivers/gpu/drm/i915/intel_pm.c:3084 skl_update_other_pipe_wm+0xe3/0x156 [i915]()
[ 1242.330694] WARN_ON(!wm_changed)
[ 1242.330697] Modules linked in: dm_mod snd_hda_codec_hdmi ppdev snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel pcspkr snd_hda_controller snd_hda_codec snd_
hwdep i2c_i801 snd_pcm snd_timer snd soundcore wmi battery parport_pc parport ac acpi_cpufreq i915 button video drm_kms_helper drm cfbfillrect cfbimgblt cfbcopyarea
[ 1242.330728] CPU: 0 PID: 1361 Comm: kworker/0:2 Not tainted 3.19.0-rc7_drm-intel-nightly_b4442e_20150208+ #198
[ 1242.330732] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.86C.B068.R00.1501090908 01/09/2015
[ 1242.330757] Workqueue: events i915_hotplug_work_func [i915]
[ 1242.330760] 0000000000000000 0000000000000009 ffffffff8179a69b ffff88009b95b808
[ 1242.330764] ffffffff8103bdec ffff880143e7991c ffffffffa008d5f4 ffff88009bba1000
[ 1242.330768] ffff880143e79918 ffff88009b95b8d0 ffff880148813800 ffff880143ed6000
[ 1242.330773] Call Trace:
[ 1242.330783] [<ffffffff8179a69b>] ? dump_stack+0x40/0x50
[ 1242.330791] [<ffffffff8103bdec>] ? warn_slowpath_common+0x98/0xb0
[ 1242.330806] [<ffffffffa008d5f4>] ? skl_update_other_pipe_wm+0xe3/0x156 [i915]
[ 1242.330812] [<ffffffff8103be9c>] ? warn_slowpath_fmt+0x45/0x4a
[ 1242.330828] [<ffffffffa008d5f4>] ? skl_update_other_pipe_wm+0xe3/0x156 [i915]
[ 1242.330844] [<ffffffffa008d7a6>] ? skl_update_wm+0x13f/0x5a8 [i915]
[ 1242.330851] [<ffffffff81065284>] ? add_wait_queue+0x3c/0x3c
[ 1242.330877] [<ffffffffa00db2c8>] ? haswell_crtc_enable+0x580/0x9b2 [i915]
[ 1242.330900] [<ffffffffa00d9878>] ? __intel_set_mode+0x7e5/0x895 [i915]
[ 1242.330923] [<ffffffffa00df2d3>] ? intel_crtc_set_config+0x7d0/0xbb9 [i915]
[ 1242.330936] [<ffffffffa0024a11>] ? drm_atomic_state_clear+0xec/0x10d [drm]
[ 1242.330952] [<ffffffffa001804a>] ? drm_mode_set_config_internal+0x4e/0xd2 [drm]
[ 1242.330960] [<ffffffffa00652e2>] ? restore_fbdev_mode+0xa8/0xc3 [drm_kms_helper]
[ 1242.330968] [<ffffffffa00665ff>] ? drm_fb_helper_restore_fbdev_mode_unlocked+0x1f/0x56 [drm_kms_helper]
[ 1242.330975] [<ffffffffa0066664>] ? drm_fb_helper_set_par+0x2e/0x33 [drm_kms_helper]
[ 1242.330982] [<ffffffffa00665da>] ? drm_fb_helper_hotplug_event+0xa2/0xa8 [drm_kms_helper]
[ 1242.330989] [<ffffffff8104d128>] ? process_one_work+0x1ad/0x31a
[ 1242.330995] [<ffffffff8104d4ef>] ? worker_thread+0x235/0x330
[ 1242.331001] [<ffffffff8104d2ba>] ? process_scheduled_works+0x25/0x25
[ 1242.331006] [<ffffffff81050dee>] ? kthread+0xc5/0xcd
[ 1242.331011] [<ffffffff81050d29>] ? kthread_freez...

*** Bug 89056 has been marked as a duplicate of this bug. ***

(In reply to Jani Nikula from comment #1)
> *** Bug 89056 has been marked as a duplicate of this bug. ***

There, the cause is DP/HDMI hotplug, but the end result is the same.

Just to triage the bug: this hits the (maybe over eager?) warnings: WARN_ON(!wm_changed). One would need to understand why the WM values have changed and why I didn't expected that to happen there.

This issue still exists on 04-11-testing kernel.

(In reply to liulei from comment #4)
> This issue still exists on 04-11-testing kernel.

update kernel version
uname: drm-intel-testing_b253c7_20150411_
git tag: drm-intel-testing-2015-04-10 drm-intel-nightly: 2015y-04m-10d-06h-57m-17s UTC integration manifest

seeing the same with drm-intel-next-2015-04-23, and there's also noticeable flicker to black on the top half of the screens during DPMS fade out

This issue still exists on latest testing
uname :4.0.0_drm-intel-testing_43d9c2_20150424
git tag:drm-intel-testing-2015-04-23 drm-intel-nightly: 2015y-04m-23d-19h-58m-37s UTC integration manifest

Tested on SKLY03 with the testing kernel drm-intel-testing-2015-05-08.
this problem still exists.
Output:
[ 7306.872817] ------------[ cut here ]------------
[ 7306.872852] WARNING: CPU: 2 PID: 1004 at drivers/gpu/drm/i915/intel_pm.c:3346 skl_update_other_pipe_wm+0x10b/0x148 [i915]()
[ 7306.872855] WARN_ON(!wm_changed)
[ 7306.872874] Modules linked in: dm_mod snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm ppdev serio_raw pcspkr snd_timer i2c_i801 snd soundcore wmi battery parport_pc parport ac acpi_cpufreq i915 button video drm_kms_helper drm
[ 7306.872880] CPU: 2 PID: 1004 Comm: kworker/2:1 Tainted: G U W 4.1.0-rc2_drm-intel-testing-2015-05-08+ #2
[ 7306.872882] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B082.B00.1504240146 04/24/2015
[ 7306.872891] Workqueue: events console_callback
[ 7306.872896] 0000000000000000 0000000000000009 ffffffff817a66cc ffff88016864f748
[ 7306.872899] ffffffff8103ebde ffff88016864f91a ffffffffa0083030 ffff88007bb10000
[ 7306.872902] ffff88016864f86c ffff880163628000 ffff880163b7c000 ffff88007bb1955c
[ 7306.872903] Call Trace:
[ 7306.872913] [<ffffffff817a66cc>] ? dump_stack+0x40/0x50
[ 7306.872918] [<ffffffff8103ebde>] ? warn_slowpath_common+0x98/0xb0
[ 7306.872941] [<ffffffffa0083030>] ? skl_update_other_pipe_wm+0x10b/0x148 [i915]
[ 7306.872944] [<ffffffff8103ec3b>] ? warn_slowpath_fmt+0x45/0x4a
[ 7306.872968] [<ffffffffa0083030>] ? skl_update_other_pipe_wm+0x10b/0x148 [i915]
[ 7306.872992] [<ffffffffa00831a2>] ? skl_update_wm+0x135/0x5c5 [i915]
[ 7306.872996] [<ffffffff81073917>] ? log_store+0x14f/0x196
[ 7306.873000] [<ffffffff8106a278>] ? down_trylock+0x20/0x29
[ 7306.873003] [<ffffffff810736ec>] ? console_trylock+0x10/0x55
[ 7306.873044] [<ffffffffa00d3485>] ? haswell_crtc_disable+0x271/0x2bc [i915]
[ 7306.873079] [<ffffffffa00d4fa1>] ? intel_crtc_control+0x97/0xd2 [i915]
[ 7306.873111] [<ffffffffa00d5020>] ? intel_crtc_update_dpms+0x44/0x52 [i915]
[ 7306.873144] [<ffffffffa00d99b5>] ? intel_connector_dpms+0x3f/0x4a [i915]
[ 7306.873153] [<ffffffffa0059d28>] ? drm_fb_helper_dpms.isra.5+0x8b/0xcc [drm_kms_helper]
[ 7306.873160] [<ffffffffa0059d9b>] ? drm_fb_helper_blank+0x32/0x39 [drm_kms_helper]
[ 7306.873191] [<ffffffffa00e6593>] ? intel_fbdev_blank+0x11/0x54 [i915]
[ 7306.873198] [<ffffffff813862bc>] ? fb_blank+0x53/0x86
[ 7306.873203] [<ffffffff8137f22e>] ? fbcon_blank+0x172/0x228
[ 7306.873208] [<ffffffff81381ebc>] ? bit_cursor+0x459/0x486
[ 7306.873214] [<ffffffff8108016c>] ? lock_timer_base.isra.37+0x22/0x46
[ 7306.873220] [<ffffffff81080ace>] ? try_to_del_timer_sync+0x46/0x51
[ 7306.873224] [<ffffffff813d46f3>] ? do_blank_screen+0x187/0x251
[ 7306.873260] [<ffffffff813d6a1e>] ? console_callback+0xc6/0xed
[ 7306.873264] [<ffffffff8104f985>] ? process_one_work+0x1b2/0x31d
[ 7306.873268] [<ffffffff8105026f>] ? worker_thread+0x265/0x351
[ 7306.873272] [<ffffffff8105000a>] ? cancel_delayed_work_sync+0xa/0xa
[ 7306.873276] [<ffffffff81053ee1>] ? kthread+0xce/0xd6
[ 7306.873281] [<ffffffff81053e13>] ? kthread_create_on_node+0x162/0x162
[ 7...

Tested on SKLY03 with the testing kernel drm-intel-testing-2015-05-22.
this problem still exists.

output:
------------------
[ 1319.346675] ------------[ cut here ]------------
[ 1319.346707] WARNING: CPU: 0 PID: 5404 at drivers/gpu/drm/i915/intel_pm.c:3391 skl_update_other_pipe_wm+0x10b/0x148 [i915]()
[ 1319.346712] WARN_ON(!wm_changed)
[ 1319.346732] Modules linked in: dm_mod snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ppdev snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm serio_raw pcspkr snd_timer snd i2c_i801 soundcore wmi battery parport_pc parport ac acpi_cpufreq i915 button video drm_kms_helper drm
[ 1319.346738] CPU: 0 PID: 5404 Comm: testdisplay Tainted: G U W 4.1.0-rc4_drm-intel-testing-2015-05-22+ #187
[ 1319.346740] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B082.B00.1504240146 04/24/2015
[ 1319.346745] 0000000000000000 0000000000000009 ffffffff817a6ebc ffff880004b074e8
[ 1319.346749] ffffffff8103ebde ffff8801634f9590 ffffffffa0085216 ffff880004b0760c
[ 1319.346752] ffff880004b0760c ffff880163bb4000 ffff880163be9000 ffff8801634f958c
[ 1319.346753] Call Trace:
[ 1319.346764] [<ffffffff817a6ebc>] ? dump_stack+0x40/0x50
[ 1319.346769] [<ffffffff8103ebde>] ? warn_slowpath_common+0x98/0xb0
[ 1319.346792] [<ffffffffa0085216>] ? skl_update_other_pipe_wm+0x10b/0x148 [i915]
[ 1319.346796] [<ffffffff8103ec3b>] ? warn_slowpath_fmt+0x45/0x4a
[ 1319.346819] [<ffffffffa0085216>] ? skl_update_other_pipe_wm+0x10b/0x148 [i915]
[ 1319.346842] [<ffffffffa0085388>] ? skl_update_wm+0x135/0x5f9 [i915]
[ 1319.346846] [<ffffffff8106a228>] ? down_trylock+0x20/0x29
[ 1319.346850] [<ffffffff8107369c>] ? console_trylock+0x10/0x55
[ 1319.346854] [<ffffffff81074e31>] ? vprintk_emit+0x30f/0x36f
[ 1319.346889] [<ffffffffa00d8a5c>] ? haswell_crtc_enable+0x52c/0x94c [i915]
[ 1319.346922] [<ffffffffa00d65f0>] ? __intel_set_mode+0x900/0x93a [i915]
[ 1319.346953] [<ffffffffa00dbe46>] ? intel_crtc_set_config+0x3f2/0x53d [i915]
[ 1319.346967] [<ffffffffa00184db>] ? drm_modeset_lock+0x4e/0xa3 [drm]
[ 1319.346988] [<ffffffffa000c229>] ? drm_mode_set_config_internal+0x4e/0xd2 [drm]
[ 1319.346996] [<ffffffffa005b13d>] ? restore_fbdev_mode+0xac/0xc3 [drm_kms_helper]
[ 1319.347011] [<ffffffffa005c93e>] ? drm_fb_helper_restore_fbdev_mode_unlocked+0x1e/0x54 [drm_kms_helper]
[ 1319.347018] [<ffffffffa005c9a2>] ? drm_fb_helper_set_par+0x2e/0x32 [drm_kms_helper]
[ 1319.347047] [<ffffffffa00e86eb>] ? intel_fbdev_set_par+0x11/0x55 [i915]
[ 1319.347053] [<ffffffff813450ad>] ? number.isra.13+0x11f/0x215
[ 1319.347060] [<ffffffff813867f5>] ? fb_set_var+0x250/0x33b
[ 1319.347064] [<ffffffff810e939c>] ? shmem_undo_range+0x455/0x46b
[ 1319.347069] [<ffffffff81345d1a>] ? vsnprintf+0x83/0x3b9
[ 1319.347084] [<ffffffff8137f3a1>] ? fbcon_blank+0x75/0x228
[ 1319.347089] [<ffffffff810df8b0>] ? file_ra_state_init+0xc/0x1d
[ 1319.347095] [<ffffffff813d6291>] ? do_unblank_screen+0xef/0x168
[ 1319.347100] [<ffffffff813ce981>] ? vt_ioctl+0x4de/0xf59
[ 1319.347106] [<ffffffff813c5f68>] ? tty_ioctl+0x954/0x9ba
[ 1319.347109] [<ffffffff811217f3>] ? do_filp_open+0x2b/0x6f
[ 13...

start X and kill X also causes Call Trace.

I am seeing the same issue in the dmesg on skl desktop system with hdmi and dp connected. I also get occasional screen flicker when transitioning across screens or windows. build is ubuntu 15.04 with tot drm-nightly from 6/1, latest drm and latest mesa.

Jim

is there any workarround for this? as someone commented on my issue https://bugs.freedesktop.org/show_bug.cgi?id=91587 its probably the same issue, and os is not usable with intel gpu

Created attachment 119531
kernel log OpenSUSE with kernel from OBS Kernel:linux-next repo drm.debug=0x0e

on my skylake system i seem to get these warnings a lot too.
Also when using KDE i get display corruption, and hard system crashes (no network login possible anymore, and nothing written to logs)

I can confirm this, with the following setup:

- Linux 4.3.0 (vanilla source tree, built with Debian's make-kpkg, kernel config derived from Debian distro kernels)
- Debian testing (stretch), amd64
- Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz
- Dual-monitor setup, one connected directly to DVI, the other attached via DisplayPort<->DVI adapter

It seems I can reliably trigger the WARN_ON(!wm_changed) condition by switching between the monitors.

Besides the backtrace-spam in my log, the system seems to run fine, no hangs, crashes, or the like (running Xorg from stretch with i3-wm).

I notice scrolling-related artifacts in conkeror, but that may be a totally unrelated issue.

Looks like same thing here.

Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz

Linux foobar 4.3.0-1-ARCH #1 SMP PREEMPT Mon Nov 2 16:52:35 CET 2015 x86_64 GNU/Linux

[ 4087.204525] ------------[ cut here ]------------
[ 4087.204554] WARNING: CPU: 0 PID: 414 at drivers/gpu/drm/i915/intel_pm.c:3668 skl_update_other_pipe_wm+0x1e7/0x1f0 [i915]()
[ 4087.204558] WARN_ON(!wm_changed)
[ 4087.204561] Modules linked in:
[ 4087.204565] nf_log_ipv6 nf_log_ipv4 nf_log_common nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nft_ct nf_conntrack nft_log nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_counter nft_meta nft_hash nft_rbtree nf_tables_inet nf_tables_ipv6 nf_tables_ipv4 nf_tables nfnetlink dm_crypt sha256_ssse3 sha256_generic hmac drbg ansi_cprng algif_skcipher af_alg intel_rapl snd_hda_codec_hdmi dm_mod snd_hda_codec_realtek snd_hda_codec_generic iosf_mbi x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul crc32c_intel aesni_intel aes_x86_64 lrw gf128mul snd_hda_intel glue_helper ablk_helper snd_hda_codec cryptd hci_uart snd_hda_core btbcm mousedev joydev btqca snd_hwdep btintel snd_pcm bluetooth mxm_wmi input_leds led_class psmouse pcspkr
[ 4087.204642] e1000e serio_raw snd_timer snd wmi ptp evdev pps_core rfkill mac_hid thermal fan pinctrl_sunrisepoint pinctrl_intel tpm_infineon battery tpm_tis mei_me mei intel_lpss_acpi intel_lpss acpi_pad tpm i2c_hid soundcore shpchp i2c_i801 processor fjes acpi_als kfifo_buf industrialio sch_fq_codel ip_tables x_tables ext4 crc16 mbcache jbd2 hid_generic usbhid hid sd_mod atkbd libps2 ahci libahci libata xhci_pci xhci_hcd scsi_mod usbcore usb_common i8042 serio i915 video button intel_gtt i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm
[ 4087.204718] CPU: 0 PID: 414 Comm: Xorg Tainted: G W 4.3.0-1-ARCH #1
[ 4087.204721] Hardware name: Gigabyte Technology Co., Ltd. Z170X-UD3/Z170X-UD3-CF, BIOS F4 10/20/2015
[ 4087.204725] 0000000000000000 00000000ce8e1234 ffff88045e77f5f8 ffffffff812bbc59
[ 4087.204731] ffff88045e77f640 ffff88045e77f630 ffffffff81074f42 ffff88045db6b000
[ 4087.204737] ffff88045e77f784 ffff88045db68000 0000000000000000 ffff88045e77f6d0
[ 4087.204743] Call Trace:
[ 4087.204755] [<ffffffff812bbc59>] dump_stack+0x4b/0x72
[ 4087.204762] [<ffffffff81074f42>] warn_slowpath_common+0x82/0xc0
[ 4087.204768] [<ffffffff81074fdc>] warn_slowpath_fmt+0x5c/0x80
[ 4087.204786] [<ffffffffa00e5b37>] skl_update_other_pipe_wm+0x1e7/0x1f0 [i915]
[ 4087.204804] [<ffffffffa00e5d03>] skl_update_wm+0x1c3/0x740 [i915]
[ 4087.204830] [<ffffffffa012aa1b>] ? gen9_read32+0xfb/0x2e0 [i915]
[ 4087.204844] [<ffffffffa00db6dc>] ? i915_get_vblank_timestamp+0x5c/0x90 [i915]
[ 4087.204863] [<ffffffffa00ea1ce>] intel_update_watermarks+0x1e/0x30 [i915]
[ 4087.204888] [<ffffffffa0146fbd>] intel_atomic_commit+0x40d/0x13d0 [i915]
[ 4087.204901] [<ffffffffa00207a5>] ? drm_atomic_check_only+0x215/0x540 [drm]
[ 4087.204912] [<ffffffffa001fb12>] ? drm_atomic_get_crtc_state+0x32/0xd0 [drm]
[ 4087.204921] [<ffffffffa0020b07>] drm_atomic_commit+0x37/0x60 [drm]
[ 4087.204931] [<ffffffffa008f60f>] drm_atomic_helper_disable_...

*** Bug 92599 has been marked as a duplicate of this bug. ***

This has also happened for the users commenting to bug: #92599 (Added as duplicate). Causes a false positive on the module reload test because the errors are spit out repeatedly even before unloading the module.

*** Bug 93118 has been marked as a duplicate of this bug. ***

Reproducible with igt BAT set. Daniel says, "This is affecting a lot of testcases and really needs to be fixed asap (before we add more atomic patches with their own issues on top)."

I also have the same issue, fresh install of kubuntu 15.10, always after booting I get several Warnings.
I use a hdmi monitor.
Last extract from dmesg:

[ 44.476443] WARNING: CPU: 0 PID: 768 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]()
[ 44.476444] WARN_ON(!wm_changed)
[ 44.476445] Modules linked in:
[ 44.476446] arc4 rtsx_usb_ms rtsx_usb_sdmmc memstick rtsx_usb bbswitch(OE) bnep hid_logitech_hidpp hid_logitech_dj hid_generic usbhid joydev snd_hda_codec_hdmi uvcvideo i2c_designware_platform acer_wmi sparse_keymap nvidia(POE) i2c_designware_core videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common snd_hda_codec_realtek snd_hda_codec_generic videodev media intel_rapl iosf_mbi x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul snd_hda_intel snd_hda_codec snd_hda_core btusb snd_hwdep btrtl snd_pcm btbcm btintel bluetooth snd_seq_midi snd_seq_midi_event snd_rawmidi aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd snd_seq ath10k_pci ath10k_core ath mac80211 snd_seq_device snd_timer idma64 virt_dma snd input_leds serio_raw cfg80211 soundcore
[ 44.476472] mei_me mei intel_lpss_pci shpchp dell_smo8800 tpm_crb wmi intel_lpss_acpi intel_lpss acpi_pad mac_hid parport_pc ppdev lp parport autofs4 uas usb_storage i915 i2c_algo_bit drm_kms_helper r8169 drm ahci mii libahci i2c_hid hid pinctrl_sunrisepoint video pinctrl_intel
[ 44.476483] CPU: 0 PID: 768 Comm: Xorg Tainted: P W OE 4.2.0-19-generic #23-Ubuntu
[ 44.476484] Hardware name: Acer Aspire V5-591G/Usopp_SLS, BIOS V1.03 10/23/2015
[ 44.476485] 0000000000000000 00000000f2cd7fef ffff88027509f628 ffffffff817e93f9
[ 44.476487] 0000000000000000 ffff88027509f680 ffff88027509f668 ffffffff8107b3d6
[ 44.476488] ffff88027509f730 ffff88027509f7d4 ffff880274872000 ffff880274873000
[ 44.476490] Call Trace:
[ 44.476493] [<ffffffff817e93f9>] dump_stack+0x45/0x57
[ 44.476496] [<ffffffff8107b3d6>] warn_slowpath_common+0x86/0xc0
[ 44.476498] [<ffffffff8107b465>] warn_slowpath_fmt+0x55/0x70
[ 44.476504] [<ffffffffc014eb9e>] skl_update_other_pipe_wm+0x1de/0x1f0 [i915]
[ 44.476510] [<ffffffffc014ed6b>] skl_update_wm+0x1bb/0x740 [i915]
[ 44.476511] [<ffffffff810bd110>] ? wake_atomic_t_function+0x60/0x60
[ 44.476518] [<ffffffffc01524be>] intel_update_watermarks+0x1e/0x30 [i915]
[ 44.476530] [<ffffffffc01b9f68>] haswell_crtc_enable+0x488/0xa90 [i915]
[ 44.476541] [<ffffffffc01b6d96>] __intel_set_mode+0x916/0xb60 [i915]
[ 44.476551] [<ffffffffc01bdb06>] intel_crtc_set_config+0x2b6/0x580 [i915]
[ 44.476561] [<ffffffffc0094ef5>] ? drm_mode_create+0x25/0x60 [drm]
[ 44.476568] [<ffffffffc008e4a6>] drm_mode_set_config_internal+0x66/0x100 [drm]
[ 44.476575] [<ffffffffc0092b39>] drm_mode_setcrtc+0x3e9/0x500 [drm]
[ 44.476580] [<ffffffffc0083495>] drm_ioctl+0x125/0x610 [drm]
[ 44.476586] [<ffffffffc0092750>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[ 44.476589] [<ffffffff81210a25>] do_vfs_ioctl+0x295/0x480
[ 44.476591] [<ffffffff81087f71>] ? __set_task_blocked+0x41/0xa0
[ 44.476592] [<ffffffff81210c89>] SyS_ioc...

It is reproducible as it only occurs with a hdmi connected monitor, without there are no error messages/warnings.

Also X server is (sometimes) unable to start because of this

I just updated the kernel to 4.3.0-040300-generic and the problem still occurs.

Regards,
Daniel

Should be fixed in nightly with
commit b900111459e2f4a538697f75b63478f3a6acec3c
Author: Maarten Lankhorst <email address hidden>
Date: Thu Nov 19 16:07:16 2015 +0100

    drm/i915/skl: Update watermarks before the crtc is disabled.

just updated to kernel 4.4.0-rc4-next-20151211-1.g34634ae-vanilla from opensuse kernel next repo, and the warnings seem to be gone. if i get some time later i will have to test with kde too if the graphic bugs and crashes are gone too.

the previous warnings are gone but now i had these 2 warnings when coming back from lunch, so guess it happened during turning the displays back on from sleep state.

Dec 15 12:38:18 linux-k058 kernel: ------------[ cut here ]------------
Dec 15 12:38:18 linux-k058 kernel: WARNING: CPU: 5 PID: 2097 at ../drivers/gpu/drm/i915/intel_display.c:12949 intel_modeset_check_state+0x573/0x8e0 [i915]()
Dec 15 12:38:18 linux-k058 kernel: pipe state doesn't match!
Dec 15 12:38:18 linux-k058 kernel: Modules linked in: cmac rfcomm ecb ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables ppdev parport_pc parport fuse vmw_vsock_vmci_transport vsock vmw_vmci af_packet bnep xfs libcrc32c nls_iso8859_1 nls_cp437 vfat fat arc4 snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel x86_pkg_temp_thermal intel_powerclamp snd_hda_codec coretemp snd_hda_core snd_hwdep kvm_intel iwlmvm snd_pcm kvm mac80211 snd_timer irqbypass crct10dif_pclmul iwlwifi crc32_pclmul ghash_clmulni_intel snd aesni_intel btusb hci_uart aes_x86_64 btrtl btqca btbcm lrw gf128mul cfg80211 glue_helper btintel pcspkr ablk_helper soundcore i2c_i801 shpchp cryptd bluetooth rfkill battery wmi pinctrl_sunrisepoint pinctrl_intel intel_lpss_acpi intel_lpss mei_me mfd_core
Dec 15 12:38:18 linux-k058 kernel: tpm_crb mei acpi_als kfifo_buf acpi_pad tpm_tis industrialio fan thermal tpm btrfs xor raid6_pq hid_generic usbhid crc32c_intel serio_raw e1000e i915 igb dca ptp pps_core i2c_algo_bit drm_kms_helper syscopyarea sysfillrect xhci_pci sysimgblt fb_sys_fops xhci_hcd usbcore drm usb_common video i2c_hid button fjes dm_mirror dm_region_hash dm_log dm_mod sg efivarfs
Dec 15 12:38:18 linux-k058 kernel: CPU: 5 PID: 2097 Comm: X Tainted: G W 4.4.0-rc4-next-20151211-1.g34634ae-vanilla #1
Dec 15 12:38:18 linux-k058 kernel: Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Z170N-WIFI-CF, BIOS F4 09/04/2015
Dec 15 12:38:18 linux-k058 kernel: ffffffffa02fe918 ffff880447ebfb10 ffffffff8138ebc2 ffff880447ebfb58
Dec 15 12:38:18 linux-k058 kernel: ffff880447ebfb48 ffffffff8107e7d6 ffff88041cae5000 ffff88045e6d9000
Dec 15 12:38:18 linux-k058 kernel: ffff88045e5d1b48 ffff88007c9fdc00 ffff88045a669400 ffff880447ebfba8
Dec 15 12:38:18 linux-k058 kernel: Call Trace:
Dec 15 12:38:18 linux-k058 kernel: [<ffffffff8138ebc2>] dump_stack+0x4b/0x79
Dec 15 12:38:18 linux-k058 kernel: [<ffffffff8107e7d6>] warn_slowpath_common+0x86/0xc0
Dec 15 12:38:18 linux-k058 kernel: [<ffffffff8107e85c>] warn_slowpath_fmt+0x4c/0x50
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa0290973>] intel_modeset_check_state+0x573/0x8e0 [i915]
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa029c513>] intel_atomic_commit+0x883/0xa00 [i915]
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa00974a0>] ? drm_atomic_set_crtc_for_connector+0x20/0x90 [drm]
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa0098137>] drm_atomic_commit+0x37/0x60 [drm]
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa019dce7>] drm_atomic_helper_set_config+0x77/0xb0 [drm_kms_helper]
Dec 15 12:38:18 linux-k058 kernel: [<ffffffffa00877f4>] drm_mode_set_config_internal+0x64/0x100 [drm]
Dec 15 12:38:18 linux...

You're missing the error lines before the pipe state mismatch. Also looks like a separate bug..

had bigger problems today in the morning after turning computer freshly on so filed a new bug already ( Bug 93393 ). when i freshly turned on the computer and booted with kernel 4.4 the 2nd display did not get initialized right, when booting with kernel 4.3 first and then rebooting it seems to work still (thats why it still worked yesterday after i installed new kernel)

Created attachment 121513
dmesg, xrandr, vbios, intel reg dump

This bug is still reproducing on my machine:
Distro: Ubuntu 16.04
CPU: Intel(R) Core(TM) i7-6700K
MB: Asus Z170-A
kernel: affb4fed39e6ec65cd44f102624885bc97fbfd70 drm-intel-nightly: 2016y-02m-04d-09h-08m-18s UTC integration manifest

This is reproducing always on boot only when I have 2 monitors (both HP EliteDisplay E241i) and only if one of them has a DP connector.

I believe I am experiencing this issue also. Dell Optiplex 7040 with Intel I7-6700 (skylake) with integrated graphics (Intel HD 530) running Ubuntu 14.04.3 LTS.

Two monitors are connected via displayport cables. Issue also occurred when using displayport to DVI adapters.

The following is logged to /var/log/syslog every time I move the mouse cursor between screens. Occasionally when I move the mouse cursor to the other screen, the screen will blank and then a few seconds later come back on. Windows are not re-arranged (implying it is not the disappearance of a screen), and similar log entries are produced. No other rendering issues or graphics issues have been noted - Unity works fine. Running tuxracer does not cause any issues.

If there is any additional information I can provide that would be helpful please let me know.

Feb 9 10:07:56 computer-name kernel: [595457.353689] ------------[ cut here ]------------
Feb 9 10:07:56 computer-name kernel: [595457.353710] WARNING: CPU: 4 PID: 1929 at /build/linux-lts-vivid-LIqOuh/linux-lts-vivid-3.19.0/ubuntu/i915/intel_pm.c:3406 skl_update_other_pipe_wm+0x210/0x220 [i915_bpo]()
Feb 9 10:07:56 computer-name kernel: [595457.353711] WARN_ON(!wm_changed)
Feb 9 10:07:56 computer-name kernel: [595457.353712] Modules linked in: snd_seq_dummy cuse uas usb_storage vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) xt_conntrack ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables x_tables nf_nat nf_conntrack br_netfilter bridge stp llc aufs pci_stub rfcomm bnep bluetooth binfmt_misc twofish_generic twofish_avx_x86_64 twofish_x86_64_3way twofish_x86_64 twofish_common xts snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi joydev snd_seq snd_seq_device x86_pkg_temp_thermal coretemp snd_timer dell_wmi sparse_keymap kvm_intel dcdbas kvm snd serio_raw soundcore 8250_fintek i2c_hid mac_hid acpi_pad i915_bpo intel_ips drm_kms_helper drm i2c_algo_bit shpchp parport_pc ppdev lp parport nls_iso8859_1 dm_crypt hid_generic usbhid hid crct10dif_pclmul crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd e1000e psmouse ptp ahci pps_core nvme libahci wmi video [last unloaded: vboxdrv]
Feb 9 10:07:56 computer-name kernel: [595457.353749] CPU: 4 PID: 1929 Comm: Xorg Tainted: G W OE 3.19.0-49-generic #55~14.04.1-Ubuntu
Feb 9 10:07:56 computer-name kernel: [595457.353750] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.0.1 09/01/2015
Feb 9 10:07:56 computer-name kernel: [595457.353751] ffffffffc05f4268 ffff88045cbb7598 ffffffff817b01b5 0000000000000000
Feb 9 10:07:56 computer-name kernel: [595457.353753] ffff88045cbb75e8 ffff88045cbb75d8 ffffffff81074dea ffff88045cbb7710
Feb 9 10:07:56 computer-name kernel: [595457.353755] ffff88045f18b000 ffff88045cbb7680 ffff88045cbb7734 ffff88045f18d000
Feb 9 10:07:56 computer-name kernel: [595457.353757] Call Trace:
Feb 9 10:07:56 computer-name kernel: [595457.353762] [<ffffffff817b01b5>] dump_stack+0x45/0x57
Feb 9 10:07:56 computer-...

Just for the record: I can also reproduce this bug reliably. Feel free to ping me if you need any sort of information, debug or quick patch testing.

Happens also on a brand new XPS 15 9550 laptop. I tried also today's kernel git (with some drm fixes for i915).

System is installed anew with Debian testing up-to-date, latest kernel code and intel video driver 2:2.99.917+git20160218-1.

Symptoms:
- system boots (lightdm)
- laptop screen blinks like crazy, monitor picture is ok (Dell P2715Q, HDMI connection)
- after logging-in everything freezes - I have to turn-off computer.

What I do to make it work:
- boot without HDMI plugged-in
- after log-in, plug-in HDMI and then I have stable environment.

This is the trace I found in syslog:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 77 at drivers/gpu/drm/i915/intel_pm.c:3553 skl_update_other_pipe_wm+0x133/0x140 [i915]()
WARN_ON(!wm_changed)
Modules linked in: ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables snd_hda_codec_hdmi dell_led snd_hda_codec_realtek snd_hda_codec_generic bbswitch(O) intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel jitterentropy_rng joydev nls_utf8 dell_wmi nls_cp437 mxm_wmi drbg snd_hda_intel vfat ansi_cprng fat snd_hda_codec snd_hda_core aesni_intel efi_pstore snd_hwdep aes_x86_64 lrw gf128mul glue_helper ablk_helper dell_laptop dcdbas snd_pcm cryptd snd_timer evdev pcspkr snd efivars idma64 serio_raw i2c_i801 soundcore virt_dma brcmfmac brcmutil cfg80211 i915 intel_gtt i2c_algo_bit mei_me drm_kms_helper mei drm syscopyarea sysfillrect sysimgblt fb_sys_fops intel_lpss_pci processor_thermal_device shpchp intel_soc_dts_iosf battery hci_uart btbcm btintel int3403_thermal bluetooth dell_smo8800 wmi video rfkill intel_lpss_acpi intel_lpss int3400_thermal int3402_thermal tpm_tis int340x_thermal_zone acpi_thermal_rel ac acpi_pad tpm intel_hid button processor ecryptfs cbc sha256_ssse3 sha256_generic hmac encrypted_keys parport_pc ppdev lp parport efivarfs autofs4 ext4 crc16 mbcache jbd2 rtsx_pci_sdmmc mmc_core crc32c_intel psmouse ahci libahci xhci_pci libata rtsx_pci nvme xhci_hcd mfd_core scsi_mod usbcore usb_common fan thermal i2c_hid hid
CPU: 1 PID: 77 Comm: kworker/u16:1 Tainted: G O 4.5.0-rc5+ #3
Hardware name: Dell Inc. XPS 15 9550/0N7TVV, BIOS 01.01.19 01/25/2016
Workqueue: events_unbound async_run_entry_fn
 0000000000000286 0000000055a2a6f3 ffffffff812e5b13 ffff88089825b7f8
 ffffffffa06617d0 ffffffff8105d93d ffff88089aa12000 ffff88089825b850
 ffff88089a2f9bd4 ffff88089abf3000 ffff88089abf33a8 ffffffff8105d9cc
Call Trace:
 [<ffffffff812e5b13>] ? dump_stack+0x5c/0x79
 [<ffffffff8105d93d>] ? warn_slowpath_common+0x7d/0xb0
 [<ffffffff8105d9cc>] ? warn_slowpath_fmt+0x5c/0x80
 [<ffffffffa059ddd3>] ? skl_update_other_pipe_wm+0x133/0x140 [i915]
 [<ffffffffa059df45>] ? skl_update_wm+0x165/0x5a0 [i915]
 [<ffffffff81575440>] ? _raw_spin_unlock_irqrestore+0x20/0x40
 [<ffffffffa062576c>] ? intel_ddi_enable_transcoder_func+0x17c/0x260 [i915]
 [<ffffffffa0609838>] ? haswell_crtc_enable+0x308/0x880 [i915]
 [<ffffffff81575440>] ? _raw_spin_unlock_irqrestore+0x20/0x40
 [<ffffffffa06052e2>] ? intel_atomic_commit+0x6d2/0x16c0 [i915]
 [<ffffffffa04d0845>] ? drm_atomic_check_only+0x185/0x600 [drm]
...

Assigning this to Gabriel since he is looking into the dmesg-warn tests results on SKL in CI system.

I'm pretty sure this happens because we wind up re-computing the same watermark values for each CRTC multiple times in a single atomic transaction (once per CRTC involved in the transaction). I'm putting together some patches that make SKL watermarks play more nicely with atomic (and eliminate this unnecessary looping); I should have those ready to post next week sometime.

I get the same error sometimes on my T460 laptop with Intel HD Graphics 520. When it occurs, it freezes the laptop completely (display turns off, no virtual terminals work, audio buffer keeps looping if present when freezing).

(In reply to Prasad H L Bhat from comment #34)
> I get the same error sometimes on my T460 laptop with Intel HD Graphics 520.
> When it occurs, it freezes the laptop completely (display turns off, no
> virtual terminals work, audio buffer keeps looping if present when freezing).

I don't think the message is the cause of your hang. The message here is a harmless warning that we're needlessly re-calculating something we shouldn't be. That's something we shouldn't be doing (and I'm in the process of fixing), but it won't actually cause any harm or trigger a system hang.

The WARN() here will often show up any time a modeset operation happens while you're using multiple displays. It sounds like something else is going wrong for you during that modeset which does cause a hang and this message just happens to be the last thing you wind up seeing.

Could you please open a new bugzilla describing the details of your setup and any actions that trigger the hang for you? It's unlikely that fixing this message here will fix your hang, so we'll want to investigate your report separately.

Thanks, Matt. You are right that this is not the primary cause for the hanging. I found out that the freeze issue that is affecting me is - https://www.reddit.com/r/thinkpad/comments/4ajgjh/t460_suspend_problem_with_linux/

BTW, I noticed that the following when the backtrace as discussed in this bug occurs on my laptop: When I switch virtual desktops the image of the window in the previous desktop is shown for some time if the current desktop does not have any windows. This happened consistently with plasma desktop of KDE 5, I have not checked others.

This series should fix this defect once it gets reviewed and merged:
   https://patchwork.freedesktop.org/series/5158/

I'm having the same issue, on exactly the same machine as Aljaž Prusnik in comment 31.

Machine is Dell XPS 9550 with i7-6700hq, kernel is 4.5.1 (from testing on Arch Linux, using the X modesetting driver)

When starting X with external display attached and using xrandr it

a) takes very long to apply the mode, over 5 seconds
b) very often leaves the internal display completely black

When I move the mouse when it is in this mode, it'll lockup, leaving me to only be able to poweroff the machine. When I redo xrandr without moving the mouse, and get it to work on both screens, it'll work without problems after that.

The lockups also happen after the screens wake up from DPMS power save.

It's not happening with a 4.4 kernel, but this one has other problems, like endless flickering on the external display after a DPMS wakeup.

I'm really eager to have that patch, but since the merge window for 4.6 is already over, does this come with 4.7 the earliest?

forgot to add: If I disable HWcursor in X config the lockups completely dissappear, but sadly the cursor also disappears whenever I stop to move the mouse :/

I've tried linux-next today (4.6.0-rc3-next-20160412) as I've read there are quite some intel driver changes there and this issue with freezing is gone. I can now log-in with monitor attached and everything still works.
The message that we posted here still appears thus confirming what Matt said in comment 35 that it doesn't have a thing to do with our reported problems.

Created attachment 122960
APL-kms_pipe_crc_pipe-c.log

Reproduced on APL when executing igt@kms_pipe_crc_basic@suspend-read-crc-pipe-c

[ 72.109585] WARNING: CPU: 0 PID: 1639 at /home/shared/kernels/drm-intel-nightly/drivers/gpu/drm/i915/intel_pm.c:3647 skl_update_other_pipe_wm+0x172/0x180 [i915]
[ 72.109586] WARN_ON(!wm_changed)

Hardware
Platform: Broxton P A0 Platform
CPU Name : Intel(R) @ 1.2 GHz (family: 6, model: 92, stepping: 8) 4 cores
SoC : BROXTON-P A0
CRB : Apollo Lake LPDDR3 RVP1A
Software
Ubuntu 15.10 64 bits
BIOS (IFWI Version): 131.10
KSC: 1.12
Kernel drm-intel-nightly 4.6.0-rc3 dc5380b from http://cgit.freedesktop.org/drm-intel/
  commit dc5380b5263ebb0bf251bb09db542585702b528b
  Author: Chris Wilson <email address hidden>
  Date: Mon Apr 11 20:43:45 2016 +0100
  drm-intel-nightly: 2016y-04m-11d-19h-43m-10s UTC integration manifest
libdrm-2.4.67-11 ea78c17 from git://anongit.freedesktop.org/mesa/drm
cairo 1.15.2 db8a7f1 from git://anongit.freedesktop.org/cairo
DMC 1.06 from https://01.org/linuxgraphics/downloads/broxton-dmc-1.06
intel-gpu-tools-1.14 c89e8db from http://anongit.freedesktop.org/git/xorg/app/intel-gpu-tools.git

(In reply to Prasad H L Bhat from comment #34)
> I get the same error sometimes on my T460 laptop with Intel HD Graphics 520.
> When it occurs, it freezes the laptop completely (display turns off, no
> virtual terminals work, audio buffer keeps looping if present when freezing).

Same in a T460p, using the Ultra Dock station connected via HDMI to an external monitor (that actually routes through DP3-1).

I see these errors multiple times, and I also experience some hangs where I see visual corruptions in monitor. Not sure this can be related, but indeed it has something to do with intel.

Christophe, please try with the patchset that Matt is pointing out to confirm we don't reproduce the issue.

Latest version of the patch series that includes a fix for this is available here:
  https://patchwork.freedesktop.org/series/5158/

Has been happening to me as well

i7-6560U running 3.19.0-58-generic

[ 2523.443953] ------------[ cut here ]------------
[ 2523.443993] WARNING: CPU: 2 PID: 1681 at /build/linux-lts-vivid-GISjUd/linux-lts-vivid-3.19.0/ubuntu/i915/intel_pm.c:3406 skl_update_other_pipe_wm+0x210/0x220 [i915_bpo]()
[ 2523.443995] WARN_ON(!wm_changed)
[ 2523.443996] Modules linked in: hid_generic cdc_ether usbnet r8152 mii dell_wmi sparse_keymap ctr ccm nvram msr dm_crypt arc4 snd_hda_codec_hdmi(OE) dell_led dell_laptop dcdbas x86_pkg_temp_thermal coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul snd_hda_codec_realtek(OE) snd_hda_codec_generic(OE) aesni_intel snd_hda_intel(OE) snd_hda_codec(OE) snd_hda_core(OE) snd_hwdep snd_pcm aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_seq_midi cryptd iwlmvm(OE) snd_seq_midi_event mac80211(OE) snd_rawmidi dm_multipath joydev scsi_dh iwlwifi(OE) serio_raw rts_cr_host(OE) cfg80211(OE) rts_cr_core(OE) uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media hid_multitouch snd_seq snd_seq_device snd_timer snd soundcore shpchp i2c_hid acpi_pad int3403_thermal int3400_thermal acpi_thermal_rel mac_hid intel_hid(OE) i915_bpo intel_ips drm_kms_helper cmac drm i2c_algo_bit parport_pc ppdev rfcomm(OE) bnep(OE) lp parport nls_iso8859_1 btrfs xor raid6_pq dm_mirror dm_region_hash dm_log usbhid hid btusb(OE) btintel(OE) bluetooth(OE) compat(OE) psmouse ahci nvme libahci wmi video
[ 2523.444052] CPU: 2 PID: 1681 Comm: Xorg Tainted: G W OE 3.19.0-58-generic #64~14.04.1-Ubuntu
[ 2523.444054] Hardware name: Dell Inc. XPS 13 9350/09JHRY, BIOS 1.3.3 03/01/2016
[ 2523.444056] 0000000000000000 ffff88046af8f588 ffffffff817b6c3d ffff88046af8f5d8
[ 2523.444059] ffffffffc0448268 ffff88046af8f5c8 ffffffff81075f3a ffff88046af8f700
[ 2523.444061] ffff880466999000 ffff88046af8f670 ffff88046af8f724 ffff880466998000
[ 2523.444064] Call Trace:
[ 2523.444071] [<ffffffff817b6c3d>] dump_stack+0x63/0x81
[ 2523.444076] [<ffffffff81075f3a>] warn_slowpath_common+0x8a/0xc0
[ 2523.444078] [<ffffffff81075fb6>] warn_slowpath_fmt+0x46/0x50
[ 2523.444097] [<ffffffffc0387720>] skl_update_other_pipe_wm+0x210/0x220 [i915_bpo]
[ 2523.444116] [<ffffffffc0387935>] skl_update_wm+0x205/0x850 [i915_bpo]
[ 2523.444141] [<ffffffffc03d25de>] ? gen9_read32+0x6e/0x310 [i915_bpo]
[ 2523.444159] [<ffffffffc0388a1e>] intel_update_watermarks+0x1e/0x30 [i915_bpo]
[ 2523.444184] [<ffffffffc03ef560>] intel_finish_crtc_commit+0x190/0x1b0 [i915_bpo]
[ 2523.444194] [<ffffffffc035ab59>] drm_atomic_helper_commit_planes_on_crtc+0x169/0x240 [drm_kms_helper]
[ 2523.444221] [<ffffffffc04095e8>] intel_atomic_commit+0x68/0x100 [i915_bpo]
[ 2523.444243] [<ffffffffc02fb247>] drm_atomic_commit+0x37/0x60 [drm]
[ 2523.444252] [<ffffffffc03591bd>] drm_atomic_helper_update_plane+0xed/0x140 [drm_kms_helper]
[ 2523.444268] [<ffffffffc02eacd0>] __setplane_internal+0x190/0x2c0 [drm]
[ 2523.444282] [<ffffffffc02eaf1c>] drm_mode_cursor_universal+0x11c/0x200 [drm]
[ 2523.444286] [<ffffffff817bc19b>] ? __ww_mutex_lock+0x1b/0x97
[ 2523.444298] [<ffffffffc02eb07c>] drm_mode_cursor_common+0x7c/0x1b0 [drm]
[ 2523.444301] [<ffffffff81081ac7>] ? __sigqueu...

*** Bug 95075 has been marked as a duplicate of this bug. ***

QA please re-test with latest patch

Note that the series linked above is fully reviewed now, but we probably want to hold off on merging it until one more issue is fixed. Apparently some BIOS can setup an unusual/unexpected initial DDB allocation that causes us problems when we try to inherit it and use it for subsequent watermark calculations. See

  https://lists.freedesktop.org/archives/intel-gfx/2016-April/093739.html

for details.

I can confirm that https://patchwork.freedesktop.org/series/5158/ fixes the problem.

Cezar, did you re-test on both APL & SKL? If so, please include your platform details.
Thanks

I thought that the platform is inferred :)

I tested only on SKL (that is my workstation). Same machine as in the attachment used to reopen the issue https://bugs.freedesktop.org/attachment.cgi?id=121513
Distro: Ubuntu 16.04
CPU: Intel(R) Core(TM) i7-6700K
MB: Asus Z170-A

I don't have access to any APL machine.

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.

Created attachment 123355
attachment-32584-0.html

Could someone please let me know how to apply this patchwork to mainstream
kernel source?

I tried on the latest 4.6-rc5 and it failed. It did work on
drm-intel-nightly though which is a not mainstream branch.

On 26 April 2016 at 07:45, <email address hidden> wrote:

> *Comment # 52 <https://bugs.freedesktop.org/show_bug.cgi?id=89055#c52> on
> bug 89055 <https://bugs.freedesktop.org/show_bug.cgi?id=89055> from
> <email address hidden> <email address hidden> *
>
> 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 are receiving this mail because:
>
> - You are on the CC list for the bug.
>
>

Unfortunately, while this patch (against drm-nightly 4.6.0-rc5) did eliminate the stack traces from my dmesg logs, it seems to have *introduced* a freezing bug. Every six to twelve hours or so the system freezes completely, audio stops, caps lock stops working (though it doesn't blink as in a panic). I assume this is a deadlock of some sort because there is no indication in any system logs that a freeze has occurred.

I have been having many issues related to suspend, so I thought at first this freeze was another manifestation of the same bug. But after happening four or five times, it just happened last night after several hours of being on without ever having been suspended. I can try the same kernel unpatched but I have tried a similar version before and I suspect the freeze is new.

Been getting this in Fedora 23 (+ testing) 64-bit ever since upgrading the hardware.

A desktop system, Intel i7 6700, built-in video, two monitors (HDMI + DVI).

The current kernel is:

Linux fiona 4.4.9-300.fc23.x86_64 #1 SMP Wed May 4 23:56:27 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

[ 1.756194] ------------[ cut here ]------------
[ 1.756271] WARNING: CPU: 0 PID: 135 at drivers/gpu/drm/i915/intel_pm.c:3601 skl_update_other_pipe_wm+0x1de/0x1f0 [i915]()
[ 1.756273] WARN_ON(!wm_changed)
[ 1.756285] Modules linked in: i915 e1000e i2c_algo_bit drm_kms_helper uas ptp serio_raw usb_storage pps_core drm nvme video i2c_hid fjes
[ 1.756290] CPU: 0 PID: 135 Comm: kworker/u16:3 Not tainted 4.4.9-300.fc23.x86_64 #1
[ 1.756292] Hardware name: System manufacturer System Product Name/Z170-A, BIOS 1702 01/28/2016
[ 1.756300] Workqueue: events_unbound async_run_entry_fn
[ 1.756305] 0000000000000286 000000007d583ed3 ffff88045e1174b0 ffffffff813b62ee
[ 1.756308] ffff88045e1174f8 ffffffffa0220bf8 ffff88045e1174e8 ffffffff810a4252
[ 1.756311] ffff88045e11761c ffff88045ba81000 ffff88045ba80000 0000000000000000
[ 1.756312] Call Trace:
[ 1.756322] [<ffffffff813b62ee>] dump_stack+0x63/0x85
[ 1.756329] [<ffffffff810a4252>] warn_slowpath_common+0x82/0xc0
[ 1.756333] [<ffffffff810a42ec>] warn_slowpath_fmt+0x5c/0x80
[ 1.756393] [<ffffffffa015bd6e>] skl_update_other_pipe_wm+0x1de/0x1f0 [i915]
[ 1.756448] [<ffffffffa015bfd2>] skl_update_wm+0x252/0x750 [i915]
[ 1.756501] [<ffffffffa01604de>] intel_update_watermarks+0x1e/0x30 [i915]
[ 1.756581] [<ffffffffa01c8b80>] haswell_crtc_enable+0x370/0x870 [i915]
[ 1.756656] [<ffffffffa01c4712>] intel_atomic_commit+0x492/0x1420 [i915]
[ 1.756694] [<ffffffffa00621ae>] ? drm_atomic_check_only+0x18e/0x590 [drm]
[ 1.756727] [<ffffffffa00625e7>] drm_atomic_commit+0x37/0x60 [drm]
[ 1.756742] [<ffffffffa00f21af>] restore_fbdev_mode+0x22f/0x260 [drm_kms_helper]
[ 1.756756] [<ffffffffa00f4383>] drm_fb_helper_restore_fbdev_mode_unlocked+0x33/0x80 [drm_kms_helper]
[ 1.756767] [<ffffffffa00f43fd>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper]
[ 1.756847] [<ffffffffa01db39a>] intel_fbdev_set_par+0x1a/0x60 [i915]
[ 1.756853] [<ffffffff814283c0>] fbcon_init+0x570/0x5f0
[ 1.756858] [<ffffffff814a9eca>] visual_init+0xca/0x130
[ 1.756861] [<ffffffff814abd61>] do_bind_con_driver+0x1c1/0x3a0
[ 1.756865] [<ffffffff814ac279>] do_take_over_console+0x149/0x1a0
[ 1.756870] [<ffffffff81424227>] do_fbcon_takeover+0x57/0xb0
[ 1.756874] [<ffffffff81428e38>] fbcon_event_notify+0x658/0x750
[ 1.756878] [<ffffffff810c369a>] notifier_call_chain+0x4a/0x70
[ 1.756882] [<ffffffff810c39d7>] __blocking_notifier_call_chain+0x47/0x60
[ 1.756885] [<ffffffff810c3a06>] blocking_notifier_call_chain+0x16/0x20
[ 1.756890] [<ffffffff8142ea8b>] fb_notifier_call_chain+0x1b/0x20
[ 1.756896] [<ffffffff81430daf>] register_framebuffer+0x20f/0x350
[ 1.756909] [<ffffffffa00f46aa>] drm_fb_helper_initial_config+0x28a/0x410 [drm_kms_helper]
[ 1.756978] [<ffffffffa01dbe9b>] intel_fbdev_initial_config+0x1b/0x20 [i915]
[ 1.756984] [<ffffffff810...

Created attachment 123545
attachment-22347-0.html

Step 2 leads to disabling of OpenGL backend which could mean performance
might be a bit lower, but your system will be very stable and usable with
this.

Hope this info helps some folks.

On 7 May 2016 at 23:54, <email address hidden> wrote:

> *Comment # 55 <https://bugs.freedesktop.org/show_bug.cgi?id=89055#c55> on
> bug 89055 <https://bugs.freedesktop.org/show_bug.cgi?id=89055> from
> <email address hidden> <email address hidden> *
>
> Been getting this in Fedora 23 (+ testing) 64-bit ever since upgrading the
> hardware.
>
> A desktop system, Intel i7 6700, built-in video, two monitors (HDMI + DVI).
>
> The current kernel is:
>
> Linux fiona 4.4.9-300.fc23.x86_64 #1 SMP Wed May 4 23:56:27 UTC 2016 x86_64
> x86_64 x86_64 GNU/Linux
>
> [ 1.756194] ------------[ cut here ]------------
> [ 1.756271] WARNING: CPU: 0 PID: 135 at drivers/gpu/drm/i915/intel_pm.c:3601
> skl_update_other_pipe_wm+0x1de/0x1f0 [i915]()
> [ 1.756273] WARN_ON(!wm_changed)
> [ 1.756285] Modules linked in: i915 e1000e i2c_algo_bit drm_kms_helper uas
> ptp serio_raw usb_storage pps_core drm nvme video i2c_hid fjes
> [ 1.756290] CPU: 0 PID: 135 Comm: kworker/u16:3 Not tainted
> 4.4.9-300.fc23.x86_64 #1
> [ 1.756292] Hardware name: System manufacturer System Product Name/Z170-A,
> BIOS 1702 01/28/2016
> [ 1.756300] Workqueue: events_unbound async_run_entry_fn
> [ 1.756305] 0000000000000286 000000007d583ed3 ffff88045e1174b0
> ffffffff813b62ee
> [ 1.756308] ffff88045e1174f8 ffffffffa0220bf8 ffff88045e1174e8
> ffffffff810a4252
> [ 1.756311] ffff88045e11761c ffff88045ba81000 ffff88045ba80000
> 0000000000000000
> [ 1.756312] Call Trace:
> [ 1.756322] [<ffffffff813b62ee>] dump_stack+0x63/0x85
> [ 1.756329] [<ffffffff810a4252>] warn_slowpath_common+0x82/0xc0
> [ 1.756333] [<ffffffff810a42ec>] warn_slowpath_fmt+0x5c/0x80
> [ 1.756393] [<ffffffffa015bd6e>] skl_update_other_pipe_wm+0x1de/0x1f0
> [i915]
> [ 1.756448] [<ffffffffa015bfd2>] skl_update_wm+0x252/0x750 [i915]
> [ 1.756501] [<ffffffffa01604de>] intel_update_watermarks+0x1e/0x30 [i915]
> [ 1.756581] [<ffffffffa01c8b80>] haswell_crtc_enable+0x370/0x870 [i915]
> [ 1.756656] [<ffffffffa01c4712>] intel_atomic_commit+0x492/0x1420 [i915]
> [ 1.756694] [<ffffffffa00621ae>] ? drm_atomic_check_only+0x18e/0x590 [drm]
> [ 1.756727] [<ffffffffa00625e7>] drm_atomic_commit+0x37/0x60 [drm]
> [ 1.756742] [<ffffffffa00f21af>] restore_fbdev_mode+0x22f/0x260
> [drm_kms_helper]
> [ 1.756756] [<ffffffffa00f4383>]
> drm_fb_helper_restore_fbdev_mode_unlocked+0x33/0x80 [drm_kms_helper]
> [ 1.756767] [<ffffffffa00f43fd>] drm_fb_helper_set_par+0x2d/0x50
> [drm_kms_helper]
> [ 1.756847] [<ffffffffa01db39a>] intel_fbdev_set_par+0x1a/0x60 [i915]
> [ 1.756853] [<ffffffff814283c0>] fbcon_init+0x570/0x5f0
> [ 1.756858] [<ffffffff814a9eca>] visual_init+0xca/0x130
> [ 1.756861] [<ffffffff814abd61>] do_bind_con_driver+0x1c1/0x3a0
> [ 1.756865] [<ffffffff814ac279>] do_take_over_console+0x149/0x1a0
> [ 1.756870] [<ffffffff81424227>] do_fbcon_takeover+0x57/0xb0
> [ 1.756874] [<ffffffff81428e38>] fb...

Here's the latest revision of the patch series to fix this bug:

  https://patchwork.freedesktop.org/series/6944/

Since I got a few offline questions last time, the patches here are meant to be applied on top of the drm-intel-nightly branch of git://anongit.freedesktop.org/drm-intel