Hi,
I am getting the lockdep warning below on a imx6q-sabred running 5.14.9.
Haven't debugged this yet, but just wanted to report in case someone has any suggestions.
Thanks,
Fabio Estevam
[ 4.913294] imx-drm display-subsystem: bound imx-ipuv3-crtc.2 (ops ipu_crtc_ops) [ 4.921640] imx-drm display-subsystem: bound imx-ipuv3-crtc.3 (ops ipu_crtc_ops) [ 4.929798] imx-drm display-subsystem: bound imx-ipuv3-crtc.6 (ops ipu_crtc_ops) [ 4.937977] imx-drm display-subsystem: bound imx-ipuv3-crtc.7 (ops ipu_crtc_ops) [ 4.946850] imx-drm display-subsystem: bound 120000.hdmi (ops dw_hdmi_imx_ops) [ 4.954685] imx-drm display-subsystem: bound ldb (ops imx_ldb_ops) [ 4.966943] [drm] Initialized imx-drm 1.0.0 20120507 for display-subsystem on minor 0 [ 5.001801] [ 5.001811] ====================================================== [ 5.001817] WARNING: possible circular locking dependency detected [ 5.001824] 5.14.9-01225-g45da36cc6fcc-dirty #1 Tainted: G W [ 5.001833] ------------------------------------------------------ [ 5.001838] kworker/u8:0/7 is trying to acquire lock: [ 5.001848] c1752080 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x40/0x294 [ 5.001903] [ 5.001903] but task is already holding lock: [ 5.001909] c176df78 (dma_fence_map){++++}-{0:0}, at: imx_drm_atomic_commit_tail+0x10/0x160 [ 5.001957] [ 5.001957] which lock already depends on the new lock. [ 5.001957] [ 5.001963] [ 5.001963] the existing dependency chain (in reverse order) is: [ 5.001968] [ 5.001968] -> #3 (dma_fence_map){++++}-{0:0}: [ 5.001993] dma_resv_lockdep+0x1c4/0x2b8 [ 5.002010] do_one_initcall+0x84/0x3b8 [ 5.002026] kernel_init_freeable+0x198/0x22c [ 5.002040] kernel_init+0x10/0x128 [ 5.002061] ret_from_fork+0x14/0x38 [ 5.002072] 0x0 [ 5.002081] [ 5.002081] -> #2 (fs_reclaim){+.+.}-{0:0}: [ 5.002105] kmem_cache_alloc+0x28/0x38c [ 5.002125] __d_alloc+0x20/0x224 [ 5.002141] d_alloc+0x10/0x60 [ 5.002152] d_alloc_parallel+0x48/0xa60 [ 5.002165] __lookup_slow+0x8c/0x178 [ 5.002184] lookup_one_len+0x98/0xd8 [ 5.002196] start_creating+0x94/0x14c [ 5.002216] debugfs_create_dir+0x10/0x100 [ 5.002231] pinctrl_init+0x1c/0xd4 [ 5.002247] do_one_initcall+0x84/0x3b8 [ 5.002259] kernel_init_freeable+0x198/0x22c [ 5.002271] kernel_init+0x10/0x128 [ 5.002286] ret_from_fork+0x14/0x38 [ 5.002296] 0x0 [ 5.002303] [ 5.002303] -> #1 (&sb->s_type->i_mutex_key#2){+.+.}-{3:3}: [ 5.002335] simple_recursive_removal+0x54/0x33c [ 5.002350] debugfs_remove+0x30/0x4c [ 5.002364] _regulator_put.part.0+0x30/0x1d8 [ 5.002383] regulator_put+0x2c/0x3c [ 5.002395] release_nodes+0x50/0x190 [ 5.002415] devres_release_all+0x80/0xd4 [ 5.002426] really_probe+0xd4/0x314 [ 5.002438] __driver_probe_device+0x80/0xe4 [ 5.002449] driver_probe_device+0x30/0xd4 [ 5.002459] __driver_attach_async_helper+0x20/0x38 [ 5.002470] async_run_entry_fn+0x20/0xb4 [ 5.002483] process_one_work+0x2a0/0x7c0 [ 5.002500] worker_thread+0x30/0x510 [ 5.002512] kthread+0x154/0x17c [ 5.002526] ret_from_fork+0x14/0x38 [ 5.002537] 0x0 [ 5.002546] [ 5.002546] -> #0 (regulator_list_mutex){+.+.}-{3:3}: [ 5.002569] lock_acquire+0x13c/0x418 [ 5.002581] __mutex_lock+0x94/0x97c [ 5.002595] mutex_lock_nested+0x1c/0x24 [ 5.002605] regulator_lock_dependent+0x40/0x294 [ 5.002622] regulator_enable+0x2c/0xec [ 5.002632] panel_simple_resume+0x38/0x1f4 [ 5.002648] __rpm_callback+0x3c/0x108 [ 5.002661] rpm_callback+0x68/0x70 [ 5.002671] rpm_resume+0x604/0x7f4 [ 5.002681] __pm_runtime_resume+0x64/0x90 [ 5.002692] panel_simple_prepare+0x2c/0x50 [ 5.002703] imx_ldb_encoder_enable+0x58/0x2b0 [ 5.002715] drm_atomic_helper_commit_modeset_enables+0x230/0x26c [ 5.002734] imx_drm_atomic_commit_tail+0x3c/0x160 [ 5.002753] commit_tail+0x9c/0x18c [ 5.002766] drm_atomic_helper_commit+0x158/0x18c [ 5.002778] drm_client_modeset_commit_atomic+0x23c/0x288 [ 5.002795] drm_client_modeset_commit_locked+0x60/0x1d0 [ 5.002806] drm_client_modeset_commit+0x24/0x40 [ 5.002819] __drm_fb_helper_restore_fbdev_mode_unlocked+0x9c/0xc8 [ 5.002835] drm_fb_helper_set_par+0x38/0x68 [ 5.002845] fbcon_init+0x2bc/0x550 [ 5.002862] visual_init+0xbc/0x104 [ 5.002881] do_bind_con_driver+0x1c8/0x3b0 [ 5.002896] do_take_over_console+0x134/0x1f0 [ 5.002910] do_fbcon_takeover+0x60/0xc0 [ 5.002924] register_framebuffer+0x1c8/0x2e8 [ 5.002936] __drm_fb_helper_initial_config_and_unlock+0x3c8/0x614 [ 5.002950] drm_fbdev_client_hotplug+0xf8/0x194 [ 5.002961] drm_fbdev_generic_setup+0x9c/0x194 [ 5.002971] imx_drm_bind+0xe0/0x124 [ 5.002985] try_to_bring_up_master+0x15c/0x1a8 [ 5.003002] __component_add+0x94/0x140 [ 5.003013] imx_ldb_probe+0x32c/0x4e8 [ 5.003025] platform_probe+0x58/0xb8 [ 5.003040] really_probe+0x14c/0x314 [ 5.003050] __driver_probe_device+0x80/0xe4 [ 5.003060] driver_probe_device+0x30/0xd4 [ 5.003070] __device_attach_driver+0x8c/0xb4 [ 5.003081] bus_for_each_drv+0x80/0xd0 [ 5.003093] __device_attach+0xec/0x160 [ 5.003105] bus_probe_device+0x88/0x90 [ 5.003116] deferred_probe_work_func+0x7c/0xac [ 5.003127] process_one_work+0x2a0/0x7c0 [ 5.003143] worker_thread+0x30/0x510 [ 5.003154] kthread+0x154/0x17c [ 5.003164] ret_from_fork+0x14/0x38 [ 5.003174] 0x0 [ 5.003182] [ 5.003182] other info that might help us debug this: [ 5.003182] [ 5.003188] Chain exists of: [ 5.003188] regulator_list_mutex --> fs_reclaim --> dma_fence_map [ 5.003188] [ 5.003218] Possible unsafe locking scenario: [ 5.003218] [ 5.003222] CPU0 CPU1 [ 5.003227] ---- ---- [ 5.003232] lock(dma_fence_map); [ 5.003244] lock(fs_reclaim); [ 5.003257] lock(dma_fence_map); [ 5.003269] lock(regulator_list_mutex); [ 5.003280] [ 5.003280] *** DEADLOCK *** [ 5.003280] [ 5.003284] 13 locks held by kworker/u8:0/7: [ 5.003292] #0: c2006ca8 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1ec/0x7c0 [ 5.003331] #1: c20c9f28 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1ec/0x7c0 [ 5.003367] #2: c21448d8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x30/0x160 [ 5.003404] #3: c1769c90 (component_mutex){+.+.}-{3:3}, at: __component_add+0x44/0x140 [ 5.003440] #4: c174c8f4 (registration_lock){+.+.}-{3:3}, at: register_framebuffer+0x28/0x2e8 [ 5.003475] #5: c1618454 (console_lock){+.+.}-{0:0}, at: register_framebuffer+0x248/0x2e8 [ 5.003508] #6: c263dc48 (&fb_info->lock){+.+.}-{3:3}, at: register_framebuffer+0x1c0/0x2e8 [ 5.003543] #7: c2b8fb6c (&helper->lock){+.+.}-{3:3}, at: __drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xc8 [ 5.003578] #8: c2be90e8 (&dev->master_mutex){+.+.}-{3:3}, at: drm_master_internal_acquire+0x18/0x3c [ 5.003614] #9: c2b8fa50 (&client->modeset_mutex){+.+.}-{3:3}, at: drm_client_modeset_commit_locked+0x20/0x1d0 [ 5.003653] #10: c20c9ae0 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0x34/0x288 [ 5.003691] #11: c263c488 (crtc_ww_class_mutex){+.+.}-{3:3}, at: drm_modeset_backoff+0x90/0x228 [ 5.003734] #12: c176df78 (dma_fence_map){++++}-{0:0}, at: imx_drm_atomic_commit_tail+0x10/0x160 [ 5.003775] [ 5.003775] stack backtrace: [ 5.003783] CPU: 0 PID: 7 Comm: kworker/u8:0 Tainted: G W 5.14.9-01225-g45da36cc6fcc-dirty #1 [ 5.003797] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 5.003808] Workqueue: events_unbound deferred_probe_work_func [ 5.003831] [<c01119b0>] (unwind_backtrace) from [<c010c020>] (show_stack+0x10/0x14) [ 5.003860] [<c010c020>] (show_stack) from [<c0e76ab0>] (dump_stack_lvl+0x58/0x70) [ 5.003887] [<c0e76ab0>] (dump_stack_lvl) from [<c0188dd4>] (check_noncircular+0xf4/0x168) [ 5.003917] [<c0188dd4>] (check_noncircular) from [<c018cc78>] (__lock_acquire+0x1698/0x3208) [ 5.003938] [<c018cc78>] (__lock_acquire) from [<c018f274>] (lock_acquire+0x13c/0x418) [ 5.003955] [<c018f274>] (lock_acquire) from [<c0e88c18>] (__mutex_lock+0x94/0x97c) [ 5.003974] [<c0e88c18>] (__mutex_lock) from [<c0e8951c>] (mutex_lock_nested+0x1c/0x24) [ 5.003991] [<c0e8951c>] (mutex_lock_nested) from [<c06aecdc>] (regulator_lock_dependent+0x40/0x294) [ 5.004019] [<c06aecdc>] (regulator_lock_dependent) from [<c06b26cc>] (regulator_enable+0x2c/0xec) [ 5.004039] [<c06b26cc>] (regulator_enable) from [<c07ce850>] (panel_simple_resume+0x38/0x1f4) [ 5.004062] [<c07ce850>] (panel_simple_resume) from [<c080698c>] (__rpm_callback+0x3c/0x108) [ 5.004082] [<c080698c>] (__rpm_callback) from [<c0806ac0>] (rpm_callback+0x68/0x70) [ 5.004098] [<c0806ac0>] (rpm_callback) from [<c08065e4>] (rpm_resume+0x604/0x7f4) [ 5.004114] [<c08065e4>] (rpm_resume) from [<c0806838>] (__pm_runtime_resume+0x64/0x90) [ 5.004131] [<c0806838>] (__pm_runtime_resume) from [<c07ce69c>] (panel_simple_prepare+0x2c/0x50) [ 5.004149] [<c07ce69c>] (panel_simple_prepare) from [<c07ccfa0>] (imx_ldb_encoder_enable+0x58/0x2b0) [ 5.004169] [<c07ccfa0>] (imx_ldb_encoder_enable) from [<c07043f8>] (drm_atomic_helper_commit_modeset_enables+0x230/0x26c) [ 5.004194] [<c07043f8>] (drm_atomic_helper_commit_modeset_enables) from [<c07c8bf8>] (imx_drm_atomic_commit_tail+0x3c/0x160) [ 5.004222] [<c07c8bf8>] (imx_drm_atomic_commit_tail) from [<c07060a0>] (commit_tail+0x9c/0x18c) [ 5.004244] [<c07060a0>] (commit_tail) from [<c07062f0>] (drm_atomic_helper_commit+0x158/0x18c) [ 5.004266] [<c07062f0>] (drm_atomic_helper_commit) from [<c073b678>] (drm_client_modeset_commit_atomic+0x23c/0x288) [ 5.004290] [<c073b678>] (drm_client_modeset_commit_atomic) from [<c073b794>] (drm_client_modeset_commit_locked+0x60/0x1d0) [ 5.004311] [<c073b794>] (drm_client_modeset_commit_locked) from [<c073b928>] (drm_client_modeset_commit+0x24/0x40) [ 5.004330] [<c073b928>] (drm_client_modeset_commit) from [<c070c474>] (__drm_fb_helper_restore_fbdev_mode_unlocked+0x9c/0xc8) [ 5.004353] [<c070c474>] (__drm_fb_helper_restore_fbdev_mode_unlocked) from [<c070c508>] (drm_fb_helper_set_par+0x38/0x68) [ 5.004373] [<c070c508>] (drm_fb_helper_set_par) from [<c0677938>] (fbcon_init+0x2bc/0x550) [ 5.004395] [<c0677938>] (fbcon_init) from [<c06d7144>] (visual_init+0xbc/0x104) [ 5.004419] [<c06d7144>] (visual_init) from [<c06d8574>] (do_bind_con_driver+0x1c8/0x3b0) [ 5.004440] [<c06d8574>] (do_bind_con_driver) from [<c06d8ab8>] (do_take_over_console+0x134/0x1f0) [ 5.004462] [<c06d8ab8>] (do_take_over_console) from [<c067557c>] (do_fbcon_takeover+0x60/0xc0) [ 5.004484] [<c067557c>] (do_fbcon_takeover) from [<c066da40>] (register_framebuffer+0x1c8/0x2e8) [ 5.004503] [<c066da40>] (register_framebuffer) from [<c070be0c>] (__drm_fb_helper_initial_config_and_unlock+0x3c8/0x614) [ 5.004522] [<c070be0c>] (__drm_fb_helper_initial_config_and_unlock) from [<c070c744>] (drm_fbdev_client_hotplug+0xf8/0x194) [ 5.004541] [<c070c744>] (drm_fbdev_client_hotplug) from [<c070c87c>] (drm_fbdev_generic_setup+0x9c/0x194) [ 5.004559] [<c070c87c>] (drm_fbdev_generic_setup) from [<c07c8b78>] (imx_drm_bind+0xe0/0x124) [ 5.004583] [<c07c8b78>] (imx_drm_bind) from [<c07f0ce4>] (try_to_bring_up_master+0x15c/0x1a8) [ 5.004608] [<c07f0ce4>] (try_to_bring_up_master) from [<c07f0dc4>] (__component_add+0x94/0x140) [ 5.004628] [<c07f0dc4>] (__component_add) from [<c07cc9dc>] (imx_ldb_probe+0x32c/0x4e8) [ 5.004647] [<c07cc9dc>] (imx_ldb_probe) from [<c07fae98>] (platform_probe+0x58/0xb8) [ 5.004670] [<c07fae98>] (platform_probe) from [<c07f8748>] (really_probe+0x14c/0x314) [ 5.004690] [<c07f8748>] (really_probe) from [<c07f8990>] (__driver_probe_device+0x80/0xe4) [ 5.004709] [<c07f8990>] (__driver_probe_device) from [<c07f8a24>] (driver_probe_device+0x30/0xd4) [ 5.004728] [<c07f8a24>] (driver_probe_device) from [<c07f8d40>] (__device_attach_driver+0x8c/0xb4) [ 5.004748] [<c07f8d40>] (__device_attach_driver) from [<c07f6b0c>] (bus_for_each_drv+0x80/0xd0) [ 5.004767] [<c07f6b0c>] (bus_for_each_drv) from [<c07f8580>] (__device_attach+0xec/0x160) [ 5.004785] [<c07f8580>] (__device_attach) from [<c07f77e0>] (bus_probe_device+0x88/0x90) [ 5.004803] [<c07f77e0>] (bus_probe_device) from [<c07f7c9c>] (deferred_probe_work_func+0x7c/0xac) [ 5.004820] [<c07f7c9c>] (deferred_probe_work_func) from [<c0147cc0>] (process_one_work+0x2a0/0x7c0) [ 5.004845] [<c0147cc0>] (process_one_work) from [<c0148210>] (worker_thread+0x30/0x510) [ 5.004865] [<c0148210>] (worker_thread) from [<c0151088>] (kthread+0x154/0x17c) [ 5.004885] [<c0151088>] (kthread) from [<c010013c>] (ret_from_fork+0x14/0x38) [ 5.004904] Exception stack(0xc20c9fb0 to 0xc20c9ff8) [ 5.004916] 9fa0: 00000000 00000000 00000000 00000000 [ 5.004929] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 5.004940] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 5.054205] Console: switching to colour frame buffer device 128x48 [ 6.236262] imx-drm display-subsystem: [drm] fb0: imx-drm frame buffer device [ 6.251485] etnaviv etnaviv: bound 130000.gpu (ops gpu_ops) [ 6.257459] etnaviv etnaviv: bound 134000.gpu (ops gpu_ops) [ 6.263513] etnaviv etnaviv: bound 2204000.gpu (ops gpu_ops) [ 6.269228] etnaviv-gpu 130000.gpu: model: GC2000, revision: 5108 [ 6.275723] etnaviv-gpu 134000.gpu: model: GC320, revision: 5007 [ 6.281932] etnaviv-gpu 2204000.gpu: model: GC355, revision: 1215 [ 6.288047] etnaviv-gpu 2204000.gpu: Ignoring GPU with VG and FE2.0 [ 6.295155] [drm] Initialized etnaviv 1.3.0 20151214 for etnaviv on minor 1