https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7001/shard-iclb1/igt@kms_cursor_legacy@basic-flip-after-cursor-atomic.html

<4> [26.206212] ======================================================
<4> [26.206213] WARNING: possible circular locking dependency detected
<4> [26.206215] 5.4.0-rc1-CI-CI_DRM_7001+ #1 Tainted: G     U           
<4> [26.206216] ------------------------------------------------------
<4> [26.206217] kms_cursor_lega/1203 is trying to acquire lock:
<4> [26.206218] ffff88849038f958 (&mapping->i_mmap_rwsem){++++}, at: unmap_mapping_pages+0x48/0x130
<4> [26.206224] 
but task is already holding lock:
<4> [26.206226] ffff8884859093a0 (&vm->mutex){+.+.}, at: i915_vma_unbind+0xe6/0x4a0 [i915]
<4> [26.206272] 
which lock already depends on the new lock.

<4> [26.206273] 
the existing dependency chain (in reverse order) is:
<4> [26.206274] 
-> #3 (&vm->mutex){+.+.}:
<4> [26.206316]        i915_gem_shrinker_taints_mutex+0x6d/0xe0 [i915]
<4> [26.206358]        i915_address_space_init+0x9f/0x160 [i915]
<4> [26.206400]        i915_ggtt_init_hw+0x55/0x170 [i915]
<4> [26.206433]        i915_driver_probe+0xc24/0x15d0 [i915]
<4> [26.206466]        i915_pci_probe+0x43/0x1b0 [i915]
<4> [26.206468]        pci_device_probe+0x9e/0x120
<4> [26.206471]        really_probe+0xea/0x420
<4> [26.206472]        driver_probe_device+0x10b/0x120
<4> [26.206474]        device_driver_attach+0x4a/0x50
<4> [26.206476]        __driver_attach+0x97/0x130
<4> [26.206478]        bus_for_each_dev+0x74/0xc0
<4> [26.206479]        bus_add_driver+0x142/0x220
<4> [26.206481]        driver_register+0x56/0xf0
<4> [26.206483]        do_one_initcall+0x58/0x2ff
<4> [26.206486]        do_init_module+0x56/0x1f8
<4> [26.206488]        load_module+0x243e/0x29f0
<4> [26.206489]        __do_sys_finit_module+0xe9/0x110
<4> [26.206491]        do_syscall_64+0x4f/0x210
<4> [26.206494]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [26.206495] 
-> #2 (&dev->struct_mutex/1){+.+.}:
<4> [26.206498]        __mutex_lock+0x9a/0x9d0
<4> [26.206538]        userptr_mn_invalidate_range_start+0x1aa/0x200 [i915]
<4> [26.206540]        __mmu_notifier_invalidate_range_start+0xa3/0x180
<4> [26.206542]        unmap_vmas+0x143/0x150
<4> [26.206544]        unmap_region+0xa3/0x100
<4> [26.206546]        __do_munmap+0x25d/0x490
<4> [26.206547]        __vm_munmap+0x6e/0xc0
<4> [26.206548]        __x64_sys_munmap+0x12/0x20
<4> [26.206550]        do_syscall_64+0x4f/0x210
<4> [26.206552]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [26.206553] 
-> #1 (mmu_notifier_invalidate_range_start){+.+.}:
<4> [26.206556]        page_mkclean_one+0xda/0x210
<4> [26.206557]        rmap_walk_file+0xff/0x260
<4> [26.206559]        page_mkclean+0x9f/0xb0
<4> [26.206561]        clear_page_dirty_for_io+0xa2/0x300
<4> [26.206564]        mpage_submit_page+0x1a/0x70
<4> [26.206565]        mpage_process_page_bufs+0xe7/0x110
<4> [26.206567]        mpage_prepare_extent_to_map+0x1d2/0x2b0
<4> [26.206569]        ext4_writepages+0x592/0x1230
<4> [26.206570]        do_writepages+0x46/0xe0
<4> [26.206572]        __filemap_fdatawrite_range+0xc6/0x100
<4> [26.206574]        file_write_and_wait_range+0x3c/0x90
<4> [26.206576]        ext4_sync_file+0x154/0x500
<4> [26.206578]        do_fsync+0x33/0x60
<4> [26.206580]        __x64_sys_fsync+0xb/0x10
<4> [26.206581]        do_syscall_64+0x4f/0x210
<4> [26.206583]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [26.206584] 
-> #0 (&mapping->i_mmap_rwsem){++++}:
<4> [26.206587]        __lock_acquire+0x1328/0x15d0
<4> [26.206589]        lock_acquire+0xa7/0x1c0
<4> [26.206591]        down_write+0x33/0x70
<4> [26.206592]        unmap_mapping_pages+0x48/0x130
<4> [26.206635]        i915_vma_revoke_mmap+0x81/0x1b0 [i915]
<4> [26.206677]        i915_vma_unbind+0xee/0x4a0 [i915]
<4> [26.206717]        i915_gem_object_ggtt_pin+0xee/0x430 [i915]
<4> [26.206756]        i915_gem_object_pin_to_display_plane+0xd1/0x130 [i915]
<4> [26.206799]        intel_pin_and_fence_fb_obj+0xb3/0x230 [i915]
<4> [26.206842]        intel_plane_pin_fb+0x3c/0xd0 [i915]
<4> [26.206885]        intel_prepare_plane_fb+0x144/0x5d0 [i915]
<4> [26.206888]        drm_atomic_helper_prepare_planes+0x85/0x110
<4> [26.206930]        intel_atomic_commit+0xc6/0x2f0 [i915]
<4> [26.206932]        drm_mode_atomic_ioctl+0x847/0x930
<4> [26.206935]        drm_ioctl_kernel+0xa7/0xf0
<4> [26.206936]        drm_ioctl+0x2e1/0x390
<4> [26.206938]        do_vfs_ioctl+0xa0/0x6f0
<4> [26.206940]        ksys_ioctl+0x35/0x60
<4> [26.206942]        __x64_sys_ioctl+0x11/0x20
<4> [26.206943]        do_syscall_64+0x4f/0x210
<4> [26.206945]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [26.206946] 
other info that might help us debug this:

<4> [26.206947] Chain exists of:
  &mapping->i_mmap_rwsem --> &dev->struct_mutex/1 --> &vm->mutex

<4> [26.206950]  Possible unsafe locking scenario:

<4> [26.206950]        CPU0                    CPU1
<4> [26.206951]        ----                    ----
<4> [26.206952]   lock(&vm->mutex);
<4> [26.206954]                                lock(&dev->struct_mutex/1);
<4> [26.206955]                                lock(&vm->mutex);
<4> [26.206956]   lock(&mapping->i_mmap_rwsem);
<4> [26.206958] 
 *** DEADLOCK ***