Bug 111373

Summary: [CI][BAT] igt@i915_selftest@live_(active|workaround|gt_timelines) - dmesg-warn - Unclaimed write to register 0xa168
Product: DRI Reporter: Martin Peres <martin.peres>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: RESOLVED MOVED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: low CC: intel-gfx-bugs
Version: XOrg git   
Hardware: Other   
OS: All   
Whiteboard: ReadyForDev
i915 platform: BSW/CHT i915 features: power/Other

Description Martin Peres 2019-08-12 08:01:05 UTC
https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6669/fi-bsw-cyan/igt@i915_selftest@live_gt_timelines.html

<7> [429.591534] [drm:i915_redisable_vga_power_on [i915]] Something enabled VGA plane, disabling it
<4> [429.591817] ------------[ cut here ]------------
<4> [429.591890] Unclaimed write to register 0xa168
<4> [429.592090] WARNING: CPU: 2 PID: 413 at drivers/gpu/drm/i915/intel_uncore.c:1077 __unclaimed_reg_debug+0x40/0x50 [i915]
<4> [429.592100] Modules linked in: i915(+) amdgpu gpu_sched ttm vgem snd_hda_codec_hdmi coretemp crct10dif_pclmul crc32_pclmul btusb ghash_clmulni_intel btrtl btbcm cdc_ether btintel usbnet bluetooth r8152 mii ecdh_generic ecc snd_intel_nhlt lpc_ich snd_hda_codec snd_hwdep snd_hda_core snd_pcm pinctrl_cherryview prime_numbers [last unloaded: i915]
<4> [429.592160] CPU: 2 PID: 413 Comm: kworker/2:3 Tainted: G     U            5.3.0-rc3-CI-CI_DRM_6669+ #1
<4> [429.592167] Hardware name: GOOGLE Cyan/Cyan, BIOS MrChromebox 02/15/2018
<4> [429.592294] Workqueue: events __intel_wakeref_put_work [i915]
<4> [429.592422] RIP: 0010:__unclaimed_reg_debug+0x40/0x50 [i915]
<4> [429.592431] Code: 74 05 5b 5d 41 5c c3 45 84 e4 48 c7 c0 5a 74 7f a0 48 c7 c6 50 74 7f a0 48 0f 44 f0 89 ea 48 c7 c7 63 74 7f a0 e8 30 e1 a7 e0 <0f> 0b 83 2d 37 d8 25 00 01 5b 5d 41 5c c3 66 90 41 56 41 55 41 89
<4> [429.592438] RSP: 0018:ffffc9000048bd90 EFLAGS: 00010082
<4> [429.592446] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000003
<4> [429.592453] RDX: 0000000080000003 RSI: 0000000000000000 RDI: 00000000ffffffff
<4> [429.592459] RBP: 000000000000a168 R08: 0000000000000000 R09: 0000000000000001
<4> [429.592466] R10: ffffc9000048bd58 R11: 0000000008437e35 R12: 0000000000000000
<4> [429.592473] R13: ffff888063100d50 R14: 0000000000000002 R15: 0000000000000005
<4> [429.592480] FS:  0000000000000000(0000) GS:ffff888079900000(0000) knlGS:0000000000000000
<4> [429.592487] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [429.592494] CR2: 00007f9e797ae580 CR3: 0000000006210000 CR4: 00000000001006e0
<4> [429.592500] Call Trace:
<4> [429.592634]  fwtable_write32+0x21d/0x2f0 [i915]
<4> [429.592767]  gen6_disable_rps_interrupts+0x4d/0xa0 [i915]
<4> [429.592896]  gen6_rps_idle+0x15/0xe0 [i915]
<4> [429.593031]  __gt_park+0x83/0xe0 [i915]
<4> [429.593162]  ____intel_wakeref_put_last+0x1c/0x70 [i915]
<4> [429.593178]  process_one_work+0x245/0x610
<4> [429.593204]  worker_thread+0x37/0x380
<4> [429.593221]  ? process_one_work+0x610/0x610
<4> [429.593229]  kthread+0x119/0x130
<4> [429.593239]  ? kthread_park+0xa0/0xa0
<4> [429.593256]  ret_from_fork+0x3a/0x50
<4> [429.593291] irq event stamp: 149178
<4> [429.593300] hardirqs last  enabled at (149177): [<ffffffff819cece4>] _raw_spin_unlock_irq+0x24/0x50
<4> [429.593309] hardirqs last disabled at (149178): [<ffffffff819ceb6a>] _raw_spin_lock_irq+0xa/0x40
<4> [429.593317] softirqs last  enabled at (148858): [<ffffffff81c0033e>] __do_softirq+0x33e/0x4ae
<4> [429.593326] softirqs last disabled at (148849): [<ffffffff810b80d9>] irq_exit+0xa9/0xc0
<4> [429.593452] WARNING: CPU: 2 PID: 413 at drivers/gpu/drm/i915/intel_uncore.c:1077 __unclaimed_reg_debug+0x40/0x50 [i915]
<4> [429.593459] ---[ end trace 4ba6515005f01bc6 ]---
Comment 2 Chris Wilson 2019-08-12 09:43:44 UTC
Note that we are holding a runtime wakeref for register access during parking, and that our wakeref tracking is consistent -- it too believes that we haven't released the runtime wakeref too early.

I dare say the third party (*cough* BIOS *cough*) that re-enabled VGA behind our back also did so without device ownership leaving a MMIO_DEBUG fail behind.

Note that we never truly takeover from the BIOS here as i915.disable_displays=1 doesn't do what it says on the tin.
Comment 3 CI Bug Log 2019-08-14 06:20:35 UTC
A CI Bug Log filter associated to this bug has been updated:

{- BSW: igt@i915_selftest@live_(active|workaround|gt_timelines) - dmesg-warn - Unclaimed write to register 0xa168 -}
{+ BSW: igt@i915_selftest@live_(active|workaround|gt_timelines|mman) - dmesg-warn - Unclaimed write to register 0xa168 +}

New failures caught by the filter:

  * https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6698/fi-bsw-cyan/igt@i915_selftest@live_mman.html
  * https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6700/fi-bsw-n3050/igt@i915_selftest@live_mman.html
Comment 4 CI Bug Log 2019-08-19 07:24:19 UTC
A CI Bug Log filter associated to this bug has been updated:

{- BSW: igt@i915_selftest@live_(active|workaround|gt_timelines|mman) - dmesg-warn - Unclaimed write to register 0xa168 -}
{+ BSW: igt@i915_selftest@live_(active|workaround|gt_timelines|mman|gem) - dmesg-warn - Unclaimed write to register 0xa168 +}

New failures caught by the filter:

  * https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6726/fi-bsw-cyan/igt@i915_selftest@live_gem.html
Comment 5 Vanshidhar Konda 2019-10-21 18:20:08 UTC
This issue occurs only on the BSW platform and there doesn't seem to be any noticeable impact on the platform due to the unclaimed write on the platform. Based on this I'm setting the priority of the bug to low and severity to normal.
Comment 6 Martin Peres 2019-11-29 19:22:32 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/drm/intel/issues/363.

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