FYI, we noticed the below changes on git://anongit.freedesktop.org/drm-intel drm-intel-next-queued commit eddfcbcdc27fbecb33bff098967bbdd7ca75bfa6 ("drm/i915: Update less state during modeset.") +-------------------------------------------------------------------------+------------+------------+ +-------------------------------------------------------------------------+------------+------------+ +-------------------------------------------------------------------------+------------+------------+ [ 25.416303] PM: suspend of devices complete after 385.609 msecs [ 25.416305] PM: suspend devices took 0.386 seconds [ 25.429140] ------------[ cut here ]------------ [ 25.429161] WARNING: CPU: 2 PID: 568 at drivers/gpu/drm/i915/intel_display.c:9277 hsw_enable_pc8+0xab/0x7b0 [i915]() [ 25.429161] CRTC for pipe A enabled [ 25.429186] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver snd_hda_codec_hdmi x86_pkg_temp_thermal coretemp kvm_intel kvm crct10dif_pclmul i915 crc32_pclmul crc32c_intel ghash_clmulni_intel drm_kms_helper aesni_intel lrw gf128mul glue_helper ablk_helper snd_hda_intel cryptd ppdev snd_hda_controller snd_hda_codec snd_hda_core serio_raw snd_hwdep microcode pcspkr snd_pcm drm i2c_i801 shpchp snd_timer snd soundcore i2c_hid winbond_cir rc_core parport_pc parport sdhci_acpi sdhci mmc_core video dw_dmac dw_dmac_core i2c_designware_platform i2c_designware_core spi_pxa2xx_platform acpi_pad [ 25.429188] CPU: 2 PID: 568 Comm: kworker/u16:4 Not tainted 4.1.0-rc6-00697-geddfcbc #18 [ 25.429189] Hardware name: Intel Corporation Broadwell Client platform/WhiteTip Mountain 1, BIOS BDW-E1R1.86C.0120.R00.1504020241 04/02/2015 [ 25.429192] Workqueue: events_unbound async_run_entry_fn [ 25.429194] ffffffffa0583158 ffff88007abafbe8 ffffffff818e4f79 ffffffff81d2dcf8 [ 25.429196] ffff88007abafc38 ffff88007abafc28 ffffffff8107672a 00000000fffbc913 [ 25.429197] ffff88007a190000 ffff880137126000 ffff8800abe46380 ffff8800abe46000 [ 25.429197] Call Trace: [ 25.429202] [<ffffffff818e4f79>] dump_stack+0x4c/0x65 [ 25.429204] [<ffffffff8107672a>] warn_slowpath_common+0x8a/0xc0 [ 25.429206] [<ffffffff810767a6>] warn_slowpath_fmt+0x46/0x50 [ 25.429221] [<ffffffffa052579b>] hsw_enable_pc8+0xab/0x7b0 [i915] [ 25.429228] [<ffffffffa04ae528>] intel_suspend_complete+0x688/0x710 [i915] [ 25.429234] [<ffffffffa04ae5d2>] i915_drm_suspend_late+0x22/0x90 [i915] [ 25.429240] [<ffffffffa04ae740>] ? i915_pm_poweroff_late+0x30/0x30 [i915] [ 25.429246] [<ffffffffa04ae769>] i915_pm_suspend_late+0x29/0x30 [i915] [ 25.429249] [<ffffffff81577e2c>] dpm_run_callback+0x4c/0x130 [ 25.429251] [<ffffffff81578720>] __device_suspend_late+0xb0/0x1a0 [ 25.429254] [<ffffffff81013723>] ? __switch_to+0x263/0x5e0 [ 25.429256] [<ffffffff8157882f>] async_suspend_late+0x1f/0xa0 [ 25.429258] [<ffffffff81098e2a>] async_run_entry_fn+0x4a/0x150 [ 25.429260] [<ffffffff8108fb98>] process_one_work+0x158/0x490 [ 25.429261] [<ffffffff810907f3>] worker_thread+0x73/0x580 [ 25.429263] [<ffffffff81090780>] ? rescuer_thread+0x400/0x400 [ 25.429264] [<ffffffff81095f5f>] kthread+0xef/0x110 [ 25.429266] [<ffffffff81095e70>] ? kthread_create_on_node+0x180/0x180 [ 25.429268] [<ffffffff818ed762>] ret_from_fork+0x42/0x70 [ 25.429269] [<ffffffff81095e70>] ? kthread_create_on_node+0x180/0x180 [ 25.429270] ---[ end trace dc42b13da2872ff3 ]--- [ 25.440253] PM: late suspend of devices complete after 23.950 msecs To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Ying Huang