Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 4a8d79901d5bed0812d272c372aa40282937b50f ("drm/i915/dp: Enable Intel's HDR backlight interface (only SDR for now)") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: suspend-stress version: with following parameters: mode: freeze iterations: 10 on test machine: 4 threads Broadwell-Y with 8G memory caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag Reported-by: kernel test robot kern :warn : [ 21.137894] ------------[ cut here ]------------ kern :warn : [ 21.137897] CPU PWM1 enabled kern :warn : [ 21.137930] WARNING: CPU: 3 PID: 575 at drivers/gpu/drm/i915/display/intel_display_power.c:4902 assert_can_disable_lcpll+0x335/0x3c0 [i915] kern :warn : [ 21.138084] Modules linked in: sd_mod t10_pi sg x86_pkg_temp_thermal intel_powerclamp i915 hid_rmi rmi_core hid_multitouch coretemp intel_ra pl_msr crct10dif_pclmul wmi_bmof crc32_pclmul intel_gtt crc32c_intel ghash_clmulni_intel rapl drm_kms_helper intel_cstate ahci libahci serio_raw mei_me proces sor_thermal_device intel_uncore processor_thermal_rfim syscopyarea sysfillrect intel_soc_dts_iosf sysimgblt intel_pch_thermal hid_sensor_custom fb_sys_fops li bata bcma processor_thermal_mbox joydev mei drm processor_thermal_rapl intel_rapl_common int340x_thermal_zone i2c_hid ideapad_laptop sparse_keymap wmi rfkill video int3400_thermal acpi_thermal_rel i2c_designware_platform dw_dmac i2c_designware_core acpi_pad ip_tables kern :warn : [ 21.138148] CPU: 3 PID: 575 Comm: kworker/u8:6 Tainted: G W I 5.11.0-rc2-00745-g4a8d79901d5b #1 kern :warn : [ 21.138153] Hardware name: LENOVO 80HE/VIUU4, BIOS A6CN38WW 09/30/2014 kern :warn : [ 21.138155] Workqueue: events_unbound async_run_entry_fn kern :warn : [ 21.138161] RIP: 0010:assert_can_disable_lcpll+0x335/0x3c0 [i915] kern :info : [ 21.138263] ahci 0000:00:1f.2: pci_pm_suspend_late+0x0/0x40 returned 0 after 0 usecs kern :warn : [ 21.138296] Code: c0 75 22 e8 8d 61 cb ff e9 f3 fd ff ff e8 fd bc 6a c1 0f 0b e9 0c fd ff ff e8 f1 bc 6a c1 0f 0b e9 05 fe ff ff e8 e5 bc 6a c1 <0f> 0b e9 cf fd ff ff e8 d9 bc 6a c1 0f 0b e9 a2 fd ff ff e8 cd bc kern :warn : [ 21.138300] RSP: 0018:ffffc900006f3d58 EFLAGS: 00010282 kern :warn : [ 21.138304] RAX: 0000000000000000 RBX: ffff8881451002e8 RCX: 0000000000000027 kern :warn : [ 21.138307] RDX: 0000000000000027 RSI: 0000000000000002 RDI: ffff888249397cf8 kern :warn : [ 21.138310] RBP: ffff888145100000 R08: ffff888249397cf0 R09: ffffc900006f3cf0 kern :warn : [ 21.138313] R10: 0000000000000001 R11: 3030302035313969 R12: ffff8881451007f0 kern :warn : [ 21.138316] R13: ffff888145106c60 R14: 0000000000000002 R15: 0000000000000000 kern :warn : [ 21.138319] FS: 0000000000000000(0000) GS:ffff888249380000(0000) knlGS:0000000000000000 kern :warn : [ 21.138322] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kern :warn : [ 21.138325] CR2: 0000557c22ec68a0 CR3: 0000000004c0a003 CR4: 00000000003706e0 kern :warn : [ 21.138329] Call Trace: kern :warn : [ 21.138334] hsw_disable_lcpll+0x22/0x280 [i915] kern :warn : [ 21.138479] i915_drm_suspend_late+0x5e/0x100 [i915] kern :warn : [ 21.138578] ? pci_pm_poweroff_late+0x40/0x40 kern :warn : [ 21.138582] dpm_run_callback+0x4c/0x140 kern :warn : [ 21.138590] __device_suspend_late+0x98/0x1a0 kern :warn : [ 21.138596] async_suspend_late+0x1b/0xa0 kern :warn : [ 21.138602] async_run_entry_fn+0x39/0x160 kern :warn : [ 21.138608] process_one_work+0x1ed/0x3c0 kern :warn : [ 21.138612] worker_thread+0x50/0x3c0 kern :warn : [ 21.138617] ? process_one_work+0x3c0/0x3c0 kern :warn : [ 21.138620] kthread+0x116/0x160 kern :warn : [ 21.138626] ? kthread_park+0xa0/0xa0 kern :warn : [ 21.138631] ret_from_fork+0x22/0x30 kern :warn : [ 21.138640] ---[ end trace a93fe4d40a5a37bb ]--- To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Oliver Sang