igt@i915_selftest@mock_requests`- WARNING: CPU: 0 PID: 9 at kernel/workqueue.c:1410 __queue_work+0x542/0x660

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7540/shard-glk1/igt@i915_selftest@mock_requests.html

<4> [1722.073594] WARNING: CPU: 0 PID: 9 at kernel/workqueue.c:1410 __queue_work+0x542/0x660
<4> [1722.073597] Modules linked in: i915(+) vgem mei_hdcp x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul snd_hda_codec_hdmi btusb btrtl ghash_clmulni_intel btbcm btintel snd_hda_codec_realtek snd_hda_codec_generic bluetooth ecdh_generic ecc r8169 realtek i2c_hid snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core snd_pcm mei_me pinctrl_geminilake pinctrl_intel mei prime_numbers [last unloaded: i915]
<4> [1722.073628] CPU: 0 PID: 9 Comm: ksoftirqd/0 Tainted: G     U            5.5.0-rc1-CI-CI_DRM_7540+ #1
<4> [1722.073630] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
<4> [1722.073634] RIP: 0010:__queue_work+0x542/0x660
<4> [1722.073638] Code: 00 75 27 65 48 8b 3c 25 00 7f 01 00 f6 47 24 20 74 18 e8 61 81 00 00 48 85 c0 74 0e 48 8b 40 20 4c 3b 60 08 0f 84 1a fb ff ff <0f> 0b 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b e9 39 fc
<4> [1722.073640] RSP: 0018:ffffc90000077da8 EFLAGS: 00010006
<4> [1722.073643] RAX: 0000000080000100 RBX: ffff88820eb78808 RCX: 0000000000000000
<4> [1722.073646] RDX: 0000000080000101 RSI: 0000000000000000 RDI: 00000000ffffffff
<4> [1722.073648] RBP: ffffc90000077de0 R08: 0000000000000000 R09: 0000000000000001
<4> [1722.073651] R10: ffffc90000077da8 R11: 00000000ffd1f85d R12: ffff88825bc68e00
<4> [1722.073653] R13: 0000000000000010 R14: 0000000000000010 R15: ffff88820eb78848
<4> [1722.073656] FS:  0000000000000000(0000) GS:ffff888278000000(0000) knlGS:0000000000000000
<4> [1722.073658] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [1722.073661] CR2: 00007fea5d040208 CR3: 0000000005610000 CR4: 0000000000340ef0
<4> [1722.073663] Call Trace:
<4> [1722.073670]  ? delayed_work_timer_fn+0x10/0x10
<4> [1722.073674]  ? rcu_core+0x420/0x750
<4> [1722.073678]  rcu_work_rcufn+0x1c/0x30
<4> [1722.073682]  rcu_core+0x480/0x750
<4> [1722.073693]  __do_softirq+0xdf/0x47f
<4> [1722.073701]  ? smpboot_thread_fn+0x23/0x280
<4> [1722.073705]  ? smpboot_thread_fn+0x6b/0x280
<4> [1722.073709]  run_ksoftirqd+0x2b/0x50
<4> [1722.073712]  smpboot_thread_fn+0x1d3/0x280
<4> [1722.073718]  ? sort_range+0x20/0x20
<4> [1722.073721]  kthread+0x119/0x130
<4> [1722.073724]  ? kthread_park+0x80/0x80
<4> [1722.073729]  ret_from_fork+0x24/0x50
<4> [1722.073742] irq event stamp: 25355637
<4> [1722.073747] hardirqs last  enabled at (25355636): [<ffffffff81a08c67>] _raw_spin_unlock_irqrestore+0x47/0x60
<4> [1722.073750] hardirqs last disabled at (25355637): [<ffffffff810d633a>] rcu_work_rcufn+0xa/0x30
<4> [1722.073753] softirqs last  enabled at (25354932): [<ffffffff81e00385>] __do_softirq+0x385/0x47f
<4> [1722.073757] softirqs last disabled at (25354937): [<ffffffff810b917b>] run_ksoftirqd+0x2b/0x50
<4> [1722.073759] ---[ end trace af41a90f76372603 ]---
<6> [1722.174485] [IGT] i915_selftest: exiting, ret=0