1. 22 9月, 2017 2 次提交
  2. 14 9月, 2017 1 次提交
  3. 13 9月, 2017 2 次提交
  4. 08 9月, 2017 6 次提交
  5. 07 9月, 2017 2 次提交
  6. 31 8月, 2017 2 次提交
  7. 24 8月, 2017 2 次提交
  8. 19 8月, 2017 3 次提交
  9. 27 7月, 2017 2 次提交
  10. 08 7月, 2017 1 次提交
  11. 03 7月, 2017 1 次提交
    • R
      drm/i915/cfl: Fix Workarounds. · 23477289
      Rodrigo Vivi 提交于
      During the review of Coffee Lake workarounds Mika pointed out
      that WaDisableKillLogic and GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC
      should be removed from CFL and with that I should carry the rv-b.
      
      However when doing the v2 I removed another Workaround that should
      remain because although not mentioned by spec the history of hangs
      around it advocates on its favor.
      
      On some follow-up patches I continued operating on the wrong
      workardound, but Ville noticed that, so here is the fix for the
      current CFL code that is upstream already.
      
      Fixes: 46c26662 ("drm/i915/cfl: Introduce Coffee Lake workarounds.")
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
      Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
      (cherry picked from commit 98eed3d1)
      Signed-off-by: NJani Nikula <jani.nikula@intel.com>
      23477289
  12. 30 6月, 2017 1 次提交
    • R
      drm/i915/cfl: Fix Workarounds. · 98eed3d1
      Rodrigo Vivi 提交于
      During the review of Coffee Lake workarounds Mika pointed out
      that WaDisableKillLogic and GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC
      should be removed from CFL and with that I should carry the rv-b.
      
      However when doing the v2 I removed another Workaround that should
      remain because although not mentioned by spec the history of hangs
      around it advocates on its favor.
      
      On some follow-up patches I continued operating on the wrong
      workardound, but Ville noticed that, so here is the fix for the
      current CFL code that is upstream already.
      
      Fixes: 46c26662 ("drm/i915/cfl: Introduce Coffee Lake workarounds.")
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
      Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
      98eed3d1
  13. 28 6月, 2017 1 次提交
  14. 20 6月, 2017 1 次提交
  15. 17 6月, 2017 1 次提交
  16. 08 6月, 2017 1 次提交
  17. 07 6月, 2017 1 次提交
    • C
      drm/i915: Hold a wakeref for probing the ring registers · d9533f19
      Chris Wilson 提交于
      Allow intel_engine_is_idle() to be called outside of the GT wakeref by
      acquiring the device runtime pm for ourselves. This allows the function
      to act as check after we assume the engine is idle and we release the GT
      wakeref held whilst we have requests. At the moment, we do not call it
      outside of an awake context but taking the wakeref as required makes it
      more convenient to use for quick debugging in future.
      
      [ 2613.401647] RPM wakelock ref not held during HW access
      [ 2613.401684] ------------[ cut here ]------------
      [ 2613.401720] WARNING: CPU: 5 PID: 7739 at drivers/gpu/drm/i915/intel_drv.h:1787 gen6_read32+0x21f/0x2b0 [i915]
      [ 2613.401731] Modules linked in: snd_hda_intel i915 vgem snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp snd_hda_codec_realtek coretemp snd_hda_codec_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm r8169 mii mei_me lpc_ich mei prime_numbers [last unloaded: i915]
      [ 2613.401823] CPU: 5 PID: 7739 Comm: drv_missed_irq Tainted: G     U          4.12.0-rc2-CI-CI_DRM_421+ #1
      [ 2613.401825] Hardware name: MSI MS-7924/Z97M-G43(MS-7924), BIOS V1.12 02/15/2016
      [ 2613.401840] task: ffff880409e3a740 task.stack: ffffc900084dc000
      [ 2613.401861] RIP: 0010:gen6_read32+0x21f/0x2b0 [i915]
      [ 2613.401863] RSP: 0018:ffffc900084dfce8 EFLAGS: 00010292
      [ 2613.401869] RAX: 000000000000002a RBX: ffff8804016a8000 RCX: 0000000000000006
      [ 2613.401871] RDX: 0000000000000006 RSI: ffffffff81cbf2d9 RDI: ffffffff81c9e3a7
      [ 2613.401874] RBP: ffffc900084dfd18 R08: ffff880409e3afc8 R09: 0000000000000000
      [ 2613.401877] R10: 000000008a1c483f R11: 0000000000000000 R12: 000000000000209c
      [ 2613.401879] R13: 0000000000000001 R14: ffff8804016a8000 R15: ffff8804016ac150
      [ 2613.401882] FS:  00007f39ef3dd8c0(0000) GS:ffff88041fb40000(0000) knlGS:0000000000000000
      [ 2613.401885] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 2613.401887] CR2: 00000000023717c8 CR3: 00000002e7b34000 CR4: 00000000001406e0
      [ 2613.401889] Call Trace:
      [ 2613.401912]  intel_engine_is_idle+0x76/0x90 [i915]
      [ 2613.401931]  i915_gem_wait_for_idle+0xe6/0x1e0 [i915]
      [ 2613.401951]  fault_irq_set+0x40/0x90 [i915]
      [ 2613.401970]  i915_ring_test_irq_set+0x42/0x50 [i915]
      [ 2613.401976]  simple_attr_write+0xc7/0xe0
      [ 2613.401981]  full_proxy_write+0x4f/0x70
      [ 2613.401987]  __vfs_write+0x23/0x120
      [ 2613.401992]  ? rcu_read_lock_sched_held+0x75/0x80
      [ 2613.401996]  ? rcu_sync_lockdep_assert+0x2a/0x50
      [ 2613.401999]  ? __sb_start_write+0xfa/0x1f0
      [ 2613.402004]  vfs_write+0xc5/0x1d0
      [ 2613.402008]  ? trace_hardirqs_on_caller+0xe7/0x1c0
      [ 2613.402013]  SyS_write+0x44/0xb0
      [ 2613.402020]  entry_SYSCALL_64_fastpath+0x1c/0xb1
      [ 2613.402022] RIP: 0033:0x7f39eded6670
      [ 2613.402025] RSP: 002b:00007fffdcdcb1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
      [ 2613.402030] RAX: ffffffffffffffda RBX: ffffffff81470203 RCX: 00007f39eded6670
      [ 2613.402033] RDX: 0000000000000001 RSI: 000000000041bc33 RDI: 0000000000000006
      [ 2613.402036] RBP: ffffc900084dff88 R08: 00007f39ef3dd8c0 R09: 0000000000000001
      [ 2613.402038] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000041bc33
      [ 2613.402041] R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
      [ 2613.402046]  ? __this_cpu_preempt_check+0x13/0x20
      [ 2613.402052] Code: 01 9b fa e0 0f ff e9 28 fe ff ff 80 3d 6a dd 0e 00 00 0f 85 29 fe ff ff 48 c7 c7 48 19 29 a0 c6 05 56 dd 0e 00 01 e8 da 9a fa e0 <0f> ff e9 0f fe ff ff b9 01 00 00 00 ba 01 00 00 00 44 89 e6 48
      [ 2613.402199] ---[ end trace 31f0cfa93ab632bf ]---
      
      Fixes: 5400367a ("drm/i915: Ensure the engine is idle before manually changing HWS")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170530121334.17364-2-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      (cherry picked from commit a091d4ee)
      Signed-off-by: NJani Nikula <jani.nikula@intel.com>
      d9533f19
  18. 01 6月, 2017 1 次提交
  19. 31 5月, 2017 1 次提交
    • C
      drm/i915: Hold a wakeref for probing the ring registers · a091d4ee
      Chris Wilson 提交于
      Allow intel_engine_is_idle() to be called outside of the GT wakeref by
      acquiring the device runtime pm for ourselves. This allows the function
      to act as check after we assume the engine is idle and we release the GT
      wakeref held whilst we have requests. At the moment, we do not call it
      outside of an awake context but taking the wakeref as required makes it
      more convenient to use for quick debugging in future.
      
      [ 2613.401647] RPM wakelock ref not held during HW access
      [ 2613.401684] ------------[ cut here ]------------
      [ 2613.401720] WARNING: CPU: 5 PID: 7739 at drivers/gpu/drm/i915/intel_drv.h:1787 gen6_read32+0x21f/0x2b0 [i915]
      [ 2613.401731] Modules linked in: snd_hda_intel i915 vgem snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp snd_hda_codec_realtek coretemp snd_hda_codec_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm r8169 mii mei_me lpc_ich mei prime_numbers [last unloaded: i915]
      [ 2613.401823] CPU: 5 PID: 7739 Comm: drv_missed_irq Tainted: G     U          4.12.0-rc2-CI-CI_DRM_421+ #1
      [ 2613.401825] Hardware name: MSI MS-7924/Z97M-G43(MS-7924), BIOS V1.12 02/15/2016
      [ 2613.401840] task: ffff880409e3a740 task.stack: ffffc900084dc000
      [ 2613.401861] RIP: 0010:gen6_read32+0x21f/0x2b0 [i915]
      [ 2613.401863] RSP: 0018:ffffc900084dfce8 EFLAGS: 00010292
      [ 2613.401869] RAX: 000000000000002a RBX: ffff8804016a8000 RCX: 0000000000000006
      [ 2613.401871] RDX: 0000000000000006 RSI: ffffffff81cbf2d9 RDI: ffffffff81c9e3a7
      [ 2613.401874] RBP: ffffc900084dfd18 R08: ffff880409e3afc8 R09: 0000000000000000
      [ 2613.401877] R10: 000000008a1c483f R11: 0000000000000000 R12: 000000000000209c
      [ 2613.401879] R13: 0000000000000001 R14: ffff8804016a8000 R15: ffff8804016ac150
      [ 2613.401882] FS:  00007f39ef3dd8c0(0000) GS:ffff88041fb40000(0000) knlGS:0000000000000000
      [ 2613.401885] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 2613.401887] CR2: 00000000023717c8 CR3: 00000002e7b34000 CR4: 00000000001406e0
      [ 2613.401889] Call Trace:
      [ 2613.401912]  intel_engine_is_idle+0x76/0x90 [i915]
      [ 2613.401931]  i915_gem_wait_for_idle+0xe6/0x1e0 [i915]
      [ 2613.401951]  fault_irq_set+0x40/0x90 [i915]
      [ 2613.401970]  i915_ring_test_irq_set+0x42/0x50 [i915]
      [ 2613.401976]  simple_attr_write+0xc7/0xe0
      [ 2613.401981]  full_proxy_write+0x4f/0x70
      [ 2613.401987]  __vfs_write+0x23/0x120
      [ 2613.401992]  ? rcu_read_lock_sched_held+0x75/0x80
      [ 2613.401996]  ? rcu_sync_lockdep_assert+0x2a/0x50
      [ 2613.401999]  ? __sb_start_write+0xfa/0x1f0
      [ 2613.402004]  vfs_write+0xc5/0x1d0
      [ 2613.402008]  ? trace_hardirqs_on_caller+0xe7/0x1c0
      [ 2613.402013]  SyS_write+0x44/0xb0
      [ 2613.402020]  entry_SYSCALL_64_fastpath+0x1c/0xb1
      [ 2613.402022] RIP: 0033:0x7f39eded6670
      [ 2613.402025] RSP: 002b:00007fffdcdcb1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
      [ 2613.402030] RAX: ffffffffffffffda RBX: ffffffff81470203 RCX: 00007f39eded6670
      [ 2613.402033] RDX: 0000000000000001 RSI: 000000000041bc33 RDI: 0000000000000006
      [ 2613.402036] RBP: ffffc900084dff88 R08: 00007f39ef3dd8c0 R09: 0000000000000001
      [ 2613.402038] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000041bc33
      [ 2613.402041] R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
      [ 2613.402046]  ? __this_cpu_preempt_check+0x13/0x20
      [ 2613.402052] Code: 01 9b fa e0 0f ff e9 28 fe ff ff 80 3d 6a dd 0e 00 00 0f 85 29 fe ff ff 48 c7 c7 48 19 29 a0 c6 05 56 dd 0e 00 01 e8 da 9a fa e0 <0f> ff e9 0f fe ff ff b9 01 00 00 00 ba 01 00 00 00 44 89 e6 48
      [ 2613.402199] ---[ end trace 31f0cfa93ab632bf ]---
      
      Fixes: 5400367a ("drm/i915: Ensure the engine is idle before manually changing HWS")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170530121334.17364-2-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      a091d4ee
  20. 17 5月, 2017 3 次提交
    • C
      drm/i915: Split execlist priority queue into rbtree + linked list · 6c067579
      Chris Wilson 提交于
      All the requests at the same priority are executed in FIFO order. They
      do not need to be stored in the rbtree themselves, as they are a simple
      list within a level. If we move the requests at one priority into a list,
      we can then reduce the rbtree to the set of priorities. This should keep
      the height of the rbtree small, as the number of active priorities can not
      exceed the number of active requests and should be typically only a few.
      
      Currently, we have ~2k possible different priority levels, that may
      increase to allow even more fine grained selection. Allocating those in
      advance seems a waste (and may be impossible), so we opt for allocating
      upon first use, and freeing after its requests are depleted. To avoid
      the possibility of an allocation failure causing us to lose a request,
      we preallocate the default priority (0) and bump any request to that
      priority if we fail to allocate it the appropriate plist. Having a
      request (that is ready to run, so not leading to corruption) execute
      out-of-order is better than leaking the request (and its dependency
      tree) entirely.
      
      There should be a benefit to reducing execlists_dequeue() to principally
      using a simple list (and reducing the frequency of both rbtree iteration
      and balancing on erase) but for typical workloads, request coalescing
      should be small enough that we don't notice any change. The main gain is
      from improving PI calls to schedule, and the explicit list within a
      level should make request unwinding simpler (we just need to insert at
      the head of the list rather than the tail and not have to make the
      rbtree search more complicated).
      
      v2: Avoid use-after-free when deleting a depleted priolist
      
      v3: Michał found the solution to handling the allocation failure
      gracefully. If we disable all priority scheduling following the
      allocation failure, those requests will be executed in fifo and we will
      ensure that this request and its dependencies are in strict fifo (even
      when it doesn't realise it is only a single list). Normal scheduling is
      restored once we know the device is idle, until the next failure!
      Suggested-by: NMichał Wajdeczko <michal.wajdeczko@intel.com>
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Michał Winiarski <michal.winiarski@intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
      Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-8-chris@chris-wilson.co.uk
      6c067579
    • C
      drm/i915/execlists: Pack the count into the low bits of the port.request · 77f0d0e9
      Chris Wilson 提交于
      add/remove: 1/1 grow/shrink: 5/4 up/down: 391/-578 (-187)
      function                                     old     new   delta
      execlists_submit_ports                       262     471    +209
      port_assign.isra                               -     136    +136
      capture                                     6344    6359     +15
      reset_common_ring                            438     452     +14
      execlists_submit_request                     228     238     +10
      gen8_init_common_ring                        334     341      +7
      intel_engine_is_idle                         106     105      -1
      i915_engine_info                            2314    2290     -24
      __i915_gem_set_wedged_BKL                    485     411     -74
      intel_lrc_irq_handler                       1789    1604    -185
      execlists_update_context                     294       -    -294
      
      The most important change there is the improve to the
      intel_lrc_irq_handler and excclist_submit_ports (net improvement since
      execlists_update_context is now inlined).
      
      v2: Use the port_api() for guc as well (even though currently we do not
      pack any counters in there, yet) and hide all port->request_count inside
      the helpers.
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-5-chris@chris-wilson.co.uk
      77f0d0e9
    • A
      drm/i915/gen9: Reintroduce WaEnableYV12BugFixInHalfSliceChicken7 · 0b71cea2
      Arkadiusz Hiler 提交于
      This basically reverts commit 465418c6
      ("drm/i915/gen9: Remove WaEnableYV12BugFixInHalfSliceChicken7")
      with small addition - marking it as affecting GLK as well.
      
      It was incorrectly considered fixed in production steppings.
      
      References: HSD#2126385, HSD#2131381, HSDES#1504433555, BSID#0764
      Cc: Mika Kuoppala <mika.kuoppala@intel.com>
      Cc: Jeff McGee <jeff.mcgee@intel.com>
      Signed-off-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
      Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
      [Mika: s/KBL/GLK on commit message]
      Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170512112015.19082-1-arkadiusz.hiler@intel.com
      0b71cea2
  21. 04 5月, 2017 1 次提交
  22. 28 4月, 2017 1 次提交
    • J
      drm/i915: Sanitize engine context sizes · 63ffbcda
      Joonas Lahtinen 提交于
      Pre-calculate engine context size based on engine class and device
      generation and store it in the engine instance.
      
      v2:
      - Squash and get rid of hw_context_size (Chris)
      
      v3:
      - Move after MMIO init for probing on Gen7 and 8 (Chris)
      - Retained rounding (Tvrtko)
      v4:
      - Rebase for deferred legacy context allocation
      Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
      Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Oscar Mateo <oscar.mateo@intel.com>
      Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
      Cc: intel-gvt-dev@lists.freedesktop.org
      Acked-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
      63ffbcda
  23. 21 4月, 2017 1 次提交
  24. 12 4月, 2017 2 次提交
    • C
      drm/i915: Pretend the engine is always idle when mocking · 8968a364
      Chris Wilson 提交于
      If we have a mock engine and it has no more requests in flight, report
      it as idle as there is no hardware to contradict us! Otherwise we
      attempt to query the hw that doesn't exist and find that the hw hasn't
      set its idle bit and we get upset.
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170411234427.14841-2-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
      8968a364
    • C
      drm/i915: Lie and treat all engines as idle if wedged · a8e9a419
      Chris Wilson 提交于
      Similar to commit 8490ae20 ("drm/i915: Suppress busy status for
      engines if wedged") we also want to report intel_engine_is_idle() as
      true as well as the main intel_engines_are_idle(), as we now check that
      the engines are idle when overwriting the HWS page. This is not true
      whilst we are setting the device as wedged, at least according to our
      bookkeeping, so we have to lie to ourselves!
      
      [  383.588601] [drm:i915_reset [i915]] *ERROR* Failed to reset chip: -110
      [  383.588685] ------------[ cut here ]------------
      [  383.588755] WARNING: CPU: 0 PID: 12 at drivers/gpu/drm/i915/intel_engine_cs.c:226 intel_engine_init_global_seqno+0x222/0x290 [i915]
      [  383.588757] WARN_ON(!intel_engine_is_idle(engine))
      [  383.588759] Modules linked in: ctr ccm snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core arc4 iwldvm mac80211 snd_pcm snd_hwdep snd_seq_midi snd_seq_midi_event rfcomm bnep snd_rawmidi intel_powerclamp coretemp dm_multipath iwlwifi crct10dif_pclmul snd_seq crc32_pclmul ghash_clmulni_intel btusb aesni_intel btrtl btbcm aes_x86_64 crypto_simd cryptd btintel snd_timer glue_helper bluetooth intel_ips snd_seq_device cfg80211 snd soundcore binfmt_misc mei_me mei dm_mirror dm_region_hash dm_log i915 intel_gtt i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea prime_numbers ahci libahci drm e1000e
      [  383.588851] CPU: 0 PID: 12 Comm: migration/0 Not tainted 4.11.0-rc5+ #207
      [  383.588853] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010
      [  383.588855] Call Trace:
      [  383.588866]  dump_stack+0x63/0x90
      [  383.588871]  __warn+0xc7/0xf0
      [  383.588876]  warn_slowpath_fmt+0x4a/0x50
      [  383.588883]  ? set_next_entity+0x821/0x910
      [  383.588943]  intel_engine_init_global_seqno+0x222/0x290 [i915]
      [  383.588998]  __i915_gem_set_wedged_BKL+0xa4/0x190 [i915]
      [  383.589003]  ? __switch_to+0x215/0x390
      [  383.589008]  multi_cpu_stop+0xbb/0xe0
      [  383.589012]  ? cpu_stop_queue_work+0x90/0x90
      [  383.589016]  cpu_stopper_thread+0x82/0x110
      [  383.589021]  smpboot_thread_fn+0x137/0x190
      [  383.589026]  kthread+0xf7/0x130
      [  383.589030]  ? sort_range+0x20/0x20
      [  383.589034]  ? kthread_park+0x90/0x90
      [  383.589040]  ret_from_fork+0x2c/0x40
      
      Fixes: 2ca9faa5 ("drm/i915: Assert the engine is idle before overwiting the HWS")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/20170411190042.25662-1-chris@chris-wilson.co.uk
      a8e9a419