1. 03 11月, 2017 2 次提交
  2. 02 11月, 2017 7 次提交
  3. 01 11月, 2017 7 次提交
  4. 31 10月, 2017 8 次提交
  5. 30 10月, 2017 1 次提交
  6. 28 10月, 2017 3 次提交
  7. 27 10月, 2017 12 次提交
    • V
      drm/i915: Stop using encoder->type in intel_ddi_enable_transcoder_func() · 742745f1
      Ville Syrjälä 提交于
      intel_ddi_enable_transcoder_func() already has the crtc state so we can
      use that instead of the untrustworthy encoder->type.
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019133721.11794-5-ville.syrjala@linux.intel.comReviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      742745f1
    • V
      drm/i915: Start using output_types for DPLL selection · f49b44ab
      Ville Syrjälä 提交于
      encoder->type is not realiable for DP/HDMI so let's switch the DPLL
      selection over to using output_types.
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019133721.11794-4-ville.syrjala@linux.intel.comReviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      f49b44ab
    • V
      drm/i915: Pass crtc state to intel_prepare_dp_ddi_buffers() · 3a6d84e6
      Ville Syrjälä 提交于
      Eliminate intel_prepare_dp_ddi_buffers()'s reliance on the encoder->type
      by passing in the crtc state.
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019133721.11794-3-ville.syrjala@linux.intel.comReviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      3a6d84e6
    • V
      drm/i915: Don't use encoder->type in intel_ddi_set_pipe_settings() · 5448f53f
      Ville Syrjälä 提交于
      encoder->type isn't reliable for DP/HDMI so instead extract the correct
      type from the crtc state in intel_ddi_set_pipe_settings().
      Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019133721.11794-2-ville.syrjala@linux.intel.comReviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      5448f53f
    • C
      drm/i915: Hold rcu_read_lock when iterating over the radixtree (vma idr) · 547da76b
      Chris Wilson 提交于
      Kasan spotted
      
          [IGT] gem_tiled_pread_pwrite: exiting, ret=0
          ==================================================================
          BUG: KASAN: use-after-free in __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
          Read of size 8 at addr ffff8801359da310 by task kworker/3:2/182
      
          CPU: 3 PID: 182 Comm: kworker/3:2 Tainted: G     U          4.14.0-rc6-CI-Custom_3340+ #1
          Hardware name: Intel Corp. Geminilake/GLK RVP1 DDR4 (05), BIOS GELKRVPA.X64.0062.B30.1708222146 08/22/2017
          Workqueue: events __i915_gem_free_work [i915]
          Call Trace:
           dump_stack+0x68/0xa0
           print_address_description+0x78/0x290
           ? __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
           kasan_report+0x23d/0x350
           __asan_report_load8_noabort+0x19/0x20
           __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
           ? i915_gem_object_truncate+0x100/0x100 [i915]
           ? lock_acquire+0x380/0x380
           __i915_gem_object_put_pages+0x30d/0x530 [i915]
           __i915_gem_free_objects+0x551/0xbd0 [i915]
           ? lock_acquire+0x13e/0x380
           __i915_gem_free_work+0x4e/0x70 [i915]
           process_one_work+0x6f6/0x1590
           ? pwq_dec_nr_in_flight+0x2b0/0x2b0
           worker_thread+0xe6/0xe90
           ? pci_mmcfg_check_reserved+0x110/0x110
           kthread+0x309/0x410
           ? process_one_work+0x1590/0x1590
           ? kthread_create_on_node+0xb0/0xb0
           ret_from_fork+0x27/0x40
      
          Allocated by task 1801:
           save_stack_trace+0x1b/0x20
           kasan_kmalloc+0xee/0x190
           kasan_slab_alloc+0x12/0x20
           kmem_cache_alloc+0xdc/0x2e0
           radix_tree_node_alloc.constprop.12+0x48/0x330
           __radix_tree_create+0x274/0x480
           __radix_tree_insert+0xa2/0x610
           i915_gem_object_get_sg+0x224/0x670 [i915]
           i915_gem_object_get_page+0xb5/0x1c0 [i915]
           i915_gem_pread_ioctl+0x822/0xf60 [i915]
           drm_ioctl_kernel+0x13f/0x1c0
           drm_ioctl+0x6cf/0x980
           do_vfs_ioctl+0x184/0xf30
           SyS_ioctl+0x41/0x70
           entry_SYSCALL_64_fastpath+0x1c/0xb1
      
          Freed by task 37:
           save_stack_trace+0x1b/0x20
           kasan_slab_free+0xaf/0x190
           kmem_cache_free+0xbf/0x340
           radix_tree_node_rcu_free+0x79/0x90
           rcu_process_callbacks+0x46d/0xf40
           __do_softirq+0x21c/0x8d3
      
          The buggy address belongs to the object at ffff8801359da0f0
          which belongs to the cache radix_tree_node of size 576
          The buggy address is located 544 bytes inside of
          576-byte region [ffff8801359da0f0, ffff8801359da330)
          The buggy address belongs to the page:
          page:ffffea0004d67600 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
          flags: 0x8000000000008100(slab|head)
          raw: 8000000000008100 0000000000000000 0000000000000000 0000000100110011
          raw: ffffea0004b52920 ffffea0004b38020 ffff88015b416a80 0000000000000000
          page dumped because: kasan: bad access detected
      
          Memory state around the buggy address:
           ffff8801359da200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
           ffff8801359da280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
          >ffff8801359da300: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
      			     ^
           ffff8801359da380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
           ffff8801359da400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
          ==================================================================
          Disabling lock debugging due to kernel taint
      
      which looks like the slab containing the radixtree iter was freed as we
      traversed the tree, taking the rcu read lock across the loop should
      prevent that (deferring all the frees until the end).
      Reported-by: NTomi Sarvela <tomi.p.sarvela@intel.com>
      Fixes: d1b48c1e ("drm/i915: Replace execbuf vma ht with an idr")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171026130032.10677-2-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
      547da76b
    • C
      drm/i915: Hold rcu_read_lock when iterating over the radixtree (objects) · bea6e987
      Chris Wilson 提交于
      Kasan spotted
      
          [IGT] gem_tiled_pread_pwrite: exiting, ret=0
          ==================================================================
          BUG: KASAN: use-after-free in __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
          Read of size 8 at addr ffff8801359da310 by task kworker/3:2/182
      
          CPU: 3 PID: 182 Comm: kworker/3:2 Tainted: G     U          4.14.0-rc6-CI-Custom_3340+ #1
          Hardware name: Intel Corp. Geminilake/GLK RVP1 DDR4 (05), BIOS GELKRVPA.X64.0062.B30.1708222146 08/22/2017
          Workqueue: events __i915_gem_free_work [i915]
          Call Trace:
           dump_stack+0x68/0xa0
           print_address_description+0x78/0x290
           ? __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
           kasan_report+0x23d/0x350
           __asan_report_load8_noabort+0x19/0x20
           __i915_gem_object_reset_page_iter+0x15c/0x170 [i915]
           ? i915_gem_object_truncate+0x100/0x100 [i915]
           ? lock_acquire+0x380/0x380
           __i915_gem_object_put_pages+0x30d/0x530 [i915]
           __i915_gem_free_objects+0x551/0xbd0 [i915]
           ? lock_acquire+0x13e/0x380
           __i915_gem_free_work+0x4e/0x70 [i915]
           process_one_work+0x6f6/0x1590
           ? pwq_dec_nr_in_flight+0x2b0/0x2b0
           worker_thread+0xe6/0xe90
           ? pci_mmcfg_check_reserved+0x110/0x110
           kthread+0x309/0x410
           ? process_one_work+0x1590/0x1590
           ? kthread_create_on_node+0xb0/0xb0
           ret_from_fork+0x27/0x40
      
          Allocated by task 1801:
           save_stack_trace+0x1b/0x20
           kasan_kmalloc+0xee/0x190
           kasan_slab_alloc+0x12/0x20
           kmem_cache_alloc+0xdc/0x2e0
           radix_tree_node_alloc.constprop.12+0x48/0x330
           __radix_tree_create+0x274/0x480
           __radix_tree_insert+0xa2/0x610
           i915_gem_object_get_sg+0x224/0x670 [i915]
           i915_gem_object_get_page+0xb5/0x1c0 [i915]
           i915_gem_pread_ioctl+0x822/0xf60 [i915]
           drm_ioctl_kernel+0x13f/0x1c0
           drm_ioctl+0x6cf/0x980
           do_vfs_ioctl+0x184/0xf30
           SyS_ioctl+0x41/0x70
           entry_SYSCALL_64_fastpath+0x1c/0xb1
      
          Freed by task 37:
           save_stack_trace+0x1b/0x20
           kasan_slab_free+0xaf/0x190
           kmem_cache_free+0xbf/0x340
           radix_tree_node_rcu_free+0x79/0x90
           rcu_process_callbacks+0x46d/0xf40
           __do_softirq+0x21c/0x8d3
      
          The buggy address belongs to the object at ffff8801359da0f0
          which belongs to the cache radix_tree_node of size 576
          The buggy address is located 544 bytes inside of
          576-byte region [ffff8801359da0f0, ffff8801359da330)
          The buggy address belongs to the page:
          page:ffffea0004d67600 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
          flags: 0x8000000000008100(slab|head)
          raw: 8000000000008100 0000000000000000 0000000000000000 0000000100110011
          raw: ffffea0004b52920 ffffea0004b38020 ffff88015b416a80 0000000000000000
          page dumped because: kasan: bad access detected
      
          Memory state around the buggy address:
           ffff8801359da200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
           ffff8801359da280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
          >ffff8801359da300: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
      			     ^
           ffff8801359da380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
           ffff8801359da400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
          ==================================================================
          Disabling lock debugging due to kernel taint
      
      which looks like the slab containing the radixtree iter was freed as we
      traversed the tree, taking the rcu read lock across the loop should
      prevent that (deferring all the frees until the end).
      Reported-by: NTomi Sarvela <tomi.p.sarvela@intel.com>
      Fixes: 96d77634 ("drm/i915: Use a radixtree for random access to the object's backing storage")
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171026130032.10677-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
      bea6e987
    • C
      drm/i915: Empty the ring before disabling · 11caf551
      Chris Wilson 提交于
      An interesting snippet from Sandybridge's prm:
      
      "Although a Ring Buffer can be enabled in the non-empty state, it must
      not be disabled unless it is empty. Attempting to disable a Ring Buffer
      in the non-empty state is UNDEFINED."
      
      Let's avoid the undefined behaviour as we disable the rings prior to
      reset and resume.
      
      v2: Tell HEAD to catch up to TAIL (empty ring) first, then reset both to
      0 (supposedly while stopped).
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
      Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171027094311.30380-1-chris@chris-wilson.co.uk
      11caf551
    • J
    • J
      drm/i915/edp: read edp display control registers unconditionally · 0501a3b0
      Jani Nikula 提交于
      Per my reading of the eDP spec, DP_DPCD_DISPLAY_CONTROL_CAPABLE bit in
      DP_EDP_CONFIGURATION_CAP should be set if the eDP display control
      registers starting at offset DP_EDP_DPCD_REV are "enabled". Currently we
      check the bit before reading the registers, and DP_EDP_DPCD_REV is the
      only way to detect eDP revision.
      
      Turns out there are (likely buggy) displays that require eDP 1.4+
      features, such as supported link rates and link rate select, but do not
      have the bit set. Read the display control registers
      unconditionally. They are supposed to read zero anyway if they are not
      supported, so there should be no harm in this.
      
      This fixes the referenced bug by enabling the eDP version check, and
      thus reading of the supported link rates. The panel in question has 0 in
      DP_MAX_LINK_RATE which is only supported in eDP 1.4+. Without the
      supported link rates method we default to RBR which is insufficient for
      the panel native mode. As a curiosity, the panel also has a bogus value
      of 0x12 in DP_EDP_DPCD_REV, but that passes our check for >= DP_EDP_14
      (which is 0x03).
      
      Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103400Reported-and-tested-by: NNicolas P. <issun.artiste@gmail.com>
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: stable@vger.kernel.org
      Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
      Signed-off-by: NJani Nikula <jani.nikula@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171026142932.17737-1-jani.nikula@intel.com
      0501a3b0
    • M
      drm/i915: Calculate ironlake intermediate watermarks correctly, v2. · b6b178a7
      Maarten Lankhorst 提交于
      The watermarks it should calculate against are the old optimal watermarks.
      The currently active crtc watermarks are pure fiction, and are invalid in
      case of a nonblocking modeset, page flip enabling/disabling planes or any
      other reason.
      
      When the crtc is disabled or during a modeset the intermediate watermarks
      don't need to be programmed separately, and could be directly assigned
      to the optimal watermarks.
      
      Changes since v1:
      - Use intel_atomic_get_old_crtc_state. (ville)
      Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019151341.4579-2-maarten.lankhorst@linux.intel.com
      [mlankhorst: Add cc stable and bugzilla link, since previous patch doesn't fix issue by itself]
      Cc: stable@vger.kernel.org #v4.8+
      Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102373
      b6b178a7
    • M
      drm/i915: Do not rely on wm preservation for ILK watermarks · 28283f4f
      Maarten Lankhorst 提交于
      The original intent was to preserve watermarks as much as possible
      in intel_pipe_wm.raw_wm, and put the validated ones in intel_pipe_wm.wm.
      
      It seems this approach is insufficient and we don't always preserve
      the raw watermarks, so just use the atomic iterator we're already using
      to get a const pointer to all bound planes on the crtc.
      
      Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102373Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Cc: stable@vger.kernel.org #v4.8+
      Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
      Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20171019151341.4579-1-maarten.lankhorst@linux.intel.com
      28283f4f
    • M
      drm/i915: Cancel the modeset retry work during modeset cleanup · 886c6b86
      Manasi Navare 提交于
      During modeset cleanup on driver unload we may have a pending
      hotplug work. This needs to be canceled early during the teardown
      so that it does not fire after we have freed the connector.
      We do this after drm_kms_helper_poll_fini(dev) since this might
      trigger modeset retry work due to link retrain and before
      intel_fbdev_fini() since this work requires the lock from fbdev.
      
      If this is not done we may see something like:
      DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock))
       ------------[ cut here ]------------
       WARNING: CPU: 4 PID: 5010 at kernel/locking/mutex-debug.c:103 mutex_destroy+0x4e/0x60
       Modules linked in: i915(-) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec snd_hwdep snd_hda_core snd_pcm vgem ax88179_178
      +a usbnet mii x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel e1000e ptp pps_core prime_numbers i2c_hid
      +[last unloaded: snd_hda_intel]
       CPU: 4 PID: 5010 Comm: drv_module_relo Tainted: G     U          4.14.0-rc3-CI-CI_DRM_3186+ #1
       Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWX1.R00.X104.A03.1709140524 09/14/2017
       task: ffff8803c827aa40 task.stack: ffffc90000520000
       RIP: 0010:mutex_destroy+0x4e/0x60
       RSP: 0018:ffffc90000523d58 EFLAGS: 00010292
       RAX: 000000000000002a RBX: ffff88044fbef648 RCX: 0000000000000000
       RDX: 0000000080000001 RSI: 0000000000000001 RDI: ffffffff810f0cf0
       RBP: ffffc90000523d60 R08: 0000000000000001 R09: 0000000000000001
       R10: 000000000f21cb81 R11: 0000000000000000 R12: ffff88044f71efc8
       R13: ffffffffa02b3d20 R14: ffffffffa02b3d90 R15: ffff880459b29308
       FS:  00007f5df4d6e8c0(0000) GS:ffff88045d300000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       CR2: 000055ec51f00a18 CR3: 0000000451782006 CR4: 00000000003606e0
       DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
       Call Trace:
        drm_fb_helper_fini+0xd9/0x130
        intel_fbdev_destroy+0x12/0x60 [i915]
        intel_fbdev_fini+0x28/0x30 [i915]
        intel_modeset_cleanup+0x45/0xa0 [i915]
        i915_driver_unload+0x92/0x180 [i915]
        i915_pci_remove+0x19/0x30 [i915]
        i915_driver_unload+0x92/0x180 [i915]
        i915_pci_remove+0x19/0x30 [i915]
        pci_device_remove+0x39/0xb0
        device_release_driver_internal+0x15d/0x220
        driver_detach+0x40/0x80
        bus_remove_driver+0x58/0xd0
        driver_unregister+0x2c/0x40
        pci_unregister_driver+0x36/0xb0
        i915_exit+0x1a/0x8b [i915]
        SyS_delete_module+0x18c/0x1e0
        entry_SYSCALL_64_fastpath+0x1c/0xb1
       RIP: 0033:0x7f5df3286287
       RSP: 002b:00007fff8e107cc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
       RAX: ffffffffffffffda RBX: ffffffff81493a03 RCX: 00007f5df3286287
       RDX: 0000000000000001 RSI: 0000000000000800 RDI: 0000564c7be02e48
       RBP: ffffc90000523f88 R08: 0000000000000000 R09: 0000000000000080
       R10: 00007f5df4d6e8c0 R11: 0000000000000246 R12: 0000000000000000
       R13: 00007fff8e107eb0 R14: 0000000000000000 R15: 0000000000000000
      Or a GPF like:
      
       general protection fault: 0000 [#1] PREEMPT SMP
       Modules linked in: i915(-) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec snd_hwdep snd_hda_core snd_pcm vgem ax88179_178
      +a usbnet mii x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel e1000e ptp pps_core prime_numbers i2c_hid
      +[last unloaded: snd_hda_intel]
       CPU: 0 PID: 82 Comm: kworker/0:1 Tainted: G     U  W       4.14.0-rc3-CI-CI_DRM_3186+ #1
       Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWX1.R00.X104.A03.1709140524 09/14/2017
       Workqueue: events intel_dp_modeset_retry_work_fn [i915]
       task: ffff88045a5caa40 task.stack: ffffc90000378000
       RIP: 0010:drm_setup_crtcs+0x143/0xbf0
       RSP: 0018:ffffc9000037bd20 EFLAGS: 00010202
       RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000002 RCX: 0000000000000001
       RDX: 0000000000000001 RSI: 0000000000000780 RDI: 00000000ffffffff
       RBP: ffffc9000037bdb8 R08: 0000000000000001 R09: 0000000000000001
       R10: 0000000000000780 R11: 0000000000000000 R12: 0000000000000002
       R13: ffff88044fbef4e8 R14: 0000000000000780 R15: 0000000000000438
       FS:  0000000000000000(0000) GS:ffff88045d200000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       CR2: 000055ec51ee5168 CR3: 000000044c89d003 CR4: 00000000003606f0
       Call Trace:
        drm_fb_helper_hotplug_event.part.18+0x7e/0xc0
        drm_fb_helper_hotplug_event+0x1a/0x20
        intel_fbdev_output_poll_changed+0x1a/0x20 [i915]
        drm_kms_helper_hotplug_event+0x27/0x30
        intel_dp_modeset_retry_work_fn+0x77/0x80 [i915]
        process_one_work+0x233/0x660
        worker_thread+0x206/0x3b0
        kthread+0x152/0x190
        ? process_one_work+0x660/0x660
        ? kthread_create_on_node+0x40/0x40
        ret_from_fork+0x27/0x40
       Code: 06 00 00 45 8b 45 20 31 db 45 31 e4 45 85 c0 0f 8e 91 06 00 00 44 8b 75 94 44 8b 7d 90 49 8b 45 28 49 63 d4 44 89 f6 41 83 c4 01 <48> 8b 04 d0 44
      +89 fa 48 8b 38 48 8b 87 a8 01 00 00 ff 50 20 01
       RIP: drm_setup_crtcs+0x143/0xbf0 RSP: ffffc9000037bd20
       ---[ end trace 08901ff1a77d30c7 ]---
      
      v2:
      * Rename it to intel_hpd_poll_fini() and call drm_kms_helper_fini() inside it
      as the first step before cancel work (Chris Wilson)
      * Add GPF trace in commit message and make the function static (Maarten Lankhorst)
      Suggested-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
      Fixes: 9301397a ("drm/i915: Implement Link Rate fallback on Link training failure")
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Tony Cheng <tony.cheng@amd.com>
      Cc: Harry Wentland <Harry.wentland@amd.com>
      Cc: Jani Nikula <jani.nikula@linux.intel.com>
      Cc: Daniel Vetter <daniel.vetter@intel.com>
      Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
      Cc: Manasi Navare <manasi.d.navare@intel.com>
      Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/1509054720-25325-1-git-send-email-manasi.d.navare@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      886c6b86