Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: fe0f1e3bfdfeb53e18f1206aea4f40b9bd1f291c ("drm/i915: Shut down displays gracefully on reboot")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master


in testcase: xfstests
version: xfstests-x86_64-d41dcbd-1_20201027
with following parameters:

	disk: 4HDD
	fs: xfs
	test: xfs-group15
	ucode: 0x28

test-description: xfstests is a regression test suite for xfs and other files ystems.
test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git


on test machine: 8 threads Intel(R) Core(TM) i7-4790 v3 @ 3.60GHz with 6G 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 <oliver.sang@intel.com>


[  226.242378] WARNING: CPU: 2 PID: 1 at drivers/gpu/drm/i915/intel_runtime_pm.h:106 gen6_write32+0x170/0x200 [i915]
[  226.252605] Modules linked in: xfs dm_mod ipmi_devintf ipmi_msghandler btrfs blake2b_generic xor zstd_compress raid6_pq libcrc32c sd_mod t10_pi sg intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel i915 kvm irqbypass intel_gtt crct10dif_pclmul crc32_pclmul crc32c_intel drm_kms_helper mei_wdt ghash_clmulni_intel ahci syscopyarea rapl sysfillrect libahci sysimgblt intel_cstate fb_sys_fops mei_me drm libata dcdbas intel_uncore mei joydev video ip_tables
[  226.295727] CPU: 2 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc4-00957-gfe0f1e3bfdfeb #1
[  226.304221] Hardware name: Dell Inc. OptiPlex 9020/03CPWF, BIOS A11 04/01/2015
[  226.311435] RIP: 0010:gen6_write32+0x170/0x200 [i915]
[  226.316472] Code: e8 95 d5 ff ff e9 1c ff ff ff 80 3d 19 80 22 00 00 0f 85 d8 fe ff ff 48 c7 c7 ad 24 af c0 c6 05 05 80 22 00 01 e8 52 01 78 c0 <0f> 0b e9 be fe ff ff 80 3d f1 7f 22 00 00 0f 85 bb fe ff ff 48 c7
[  226.335189] RSP: 0018:ffffc9000002fd10 EFLAGS: 00010282
[  226.340397] RAX: 0000000000000000 RBX: ffff8881989a0808 RCX: 0000000000000da0
[  226.347510] RDX: 0000000000000001 RSI: 0000000000000096 RDI: ffffffff82fb882c
[  226.354624] RBP: 0000000000044004 R08: 0000000000000da0 R09: ffffc900100a101c
[  226.361738] R10: 0000000000aaaaaa R11: 0000000000000000 R12: 0000000000000000
[  226.368851] R13: 00000000ffffffff R14: 000000000004400c R15: 0000000000000000
[  226.375963] FS:  00007f6d8a443940(0000) GS:ffff88819ea80000(0000) knlGS:0000000000000000
[  226.384027] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  226.389756] CR2: 00007f6d8b66b660 CR3: 000000019bca6005 CR4: 00000000001706e0
[  226.396869] Call Trace:
[  226.399324]  gen3_irq_reset+0x2e/0xc0 [i915]
[  226.403596]  intel_irq_reset+0x59/0x6c0 [i915]
[  226.408040]  intel_runtime_pm_disable_interrupts+0xe/0x40 [i915]
[  226.414044]  i915_driver_shutdown+0x2e/0x40 [i915]
[  226.418825]  pci_device_shutdown+0x34/0x60
[  226.422912]  device_shutdown+0x162/0x1c2
[  226.426824]  kernel_restart+0xe/0x40
[  226.430390]  __do_sys_reboot+0x1d2/0x220
[  226.434299]  ? rcu_nocb_try_bypass+0x1f2/0x340
[  226.438731]  ? get_max_files+0x20/0x20
[  226.442472]  ? exit_to_user_mode_prepare+0x10f/0x140
[  226.447423]  do_syscall_64+0x33/0x40
[  226.450992]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  226.456028] RIP: 0033:0x7f6d8b5a0373
[  226.459594] Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 89 fa be 69 19 12 28 bf ad de e1 fe b8 a9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 e9 9a 0c 00 f7 d8
[  226.478309] RSP: 002b:00007ffc8b226e48 EFLAGS: 00000297 ORIG_RAX: 00000000000000a9
[  226.485856] RAX: ffffffffffffffda RBX: 0000000001234567 RCX: 00007f6d8b5a0373
[  226.492969] RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead
[  226.500083] RBP: 00007ffc8b226f80 R08: 000000000000021f R09: 00005650d4a8e290
[  226.507194] R10: 0000000000000000 R11: 0000000000000297 R12: 00007ffc8b226ec0
[  226.514992] R13: 00007ffc8b226eb8 R14: 0000000000000000 R15: 0000000000000000
[  226.522785] ---[ end trace c4cc4a1ec34d1367 ]---


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