INFO: task kworker/0:1:12 blocked for more than 143 seconds. Not tainted 5.3.0+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D23992 12 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xca/0x250 kernel/sched/core.c:4132 schedule_timeout+0x682/0xb20 kernel/time/timer.c:1869 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 kernel/sched/completion.c:136 flush_workqueue+0x40f/0x14b0 kernel/workqueue.c:2826 hif_detach_htc drivers/net/wireless/ath/ath6kl/usb.c:856 [inline] ath6kl_usb_power_off+0x33/0x40 drivers/net/wireless/ath/ath6kl/usb.c:1055 ath6kl_hif_power_off drivers/net/wireless/ath/ath6kl/hif-ops.h:143 [inline] ath6kl_core_init+0x274/0x10b0 drivers/net/wireless/ath/ath6kl/core.c:255 ath6kl_usb_probe+0xc7a/0x1180 drivers/net/wireless/ath/ath6kl/usb.c:1155 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0xae6/0x16f0 drivers/base/core.c:2201 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0xae6/0x16f0 drivers/base/core.c:2201 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 hub_port_connect drivers/usb/core/hub.c:5098 [inline] hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] port_event drivers/usb/core/hub.c:5359 [inline] hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:4:2760 blocked for more than 143 seconds. Not tainted 5.3.0+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:4 D23512 2760 2 0x80004000 Workqueue: events request_firmware_work_func Call Trace: schedule+0xca/0x250 kernel/sched/core.c:4132 schedule_preempt_disabled+0xc/0x20 kernel/sched/core.c:4191 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x881/0x1360 kernel/locking/mutex.c:1103 device_lock include/linux/device.h:1462 [inline] ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1077 [inline] ath9k_hif_usb_firmware_cb+0x37c/0x500 drivers/net/wireless/ath/ath9k/hif_usb.c:1210 request_firmware_work_func+0x126/0x242 drivers/base/firmware_loader/main.c:975 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:5:2769 blocked for more than 144 seconds. Not tainted 5.3.0+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:5 D23856 2769 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xca/0x250 kernel/sched/core.c:4132 schedule_timeout+0x682/0xb20 kernel/time/timer.c:1869 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x26f/0x3c0 kernel/sched/completion.c:136 flush_workqueue+0x40f/0x14b0 kernel/workqueue.c:2826 hif_detach_htc drivers/net/wireless/ath/ath6kl/usb.c:856 [inline] ath6kl_usb_power_off+0x33/0x40 drivers/net/wireless/ath/ath6kl/usb.c:1055 ath6kl_hif_power_off drivers/net/wireless/ath/ath6kl/hif-ops.h:143 [inline] ath6kl_core_init+0x274/0x10b0 drivers/net/wireless/ath/ath6kl/core.c:255 ath6kl_usb_probe+0xc7a/0x1180 drivers/net/wireless/ath/ath6kl/usb.c:1155 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0xae6/0x16f0 drivers/base/core.c:2201 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0xae6/0x16f0 drivers/base/core.c:2201 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 hub_port_connect drivers/usb/core/hub.c:5098 [inline] hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] port_event drivers/usb/core/hub.c:5359 [inline] hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 5 locks held by kworker/0:1/12: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881da20fdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5c47900 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5c47900 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881ae6f4600 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881ae6f4600 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881ceeff890 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881ceeff890 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 1 lock held by khungtaskd/23: #0: ffffffff86eff3e0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5335 5 locks held by kworker/1:2/100: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881d5d9fdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5d0ac80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5d0ac80 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881afef2c80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881afef2c80 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881afef4e10 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881afef4e10 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 1 lock held by rsyslogd/1609: #0: ffff8881d6358d60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1699: #0: ffff8881d6760090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004752e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1700: #0: ffff8881d90c0910 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004952e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1701: #0: ffff8881d6760910 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000046d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1702: #0: ffff8881d90c4d10 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004892e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1703: #0: ffff8881d911c490 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000047d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1704: #0: ffff8881d90c1190 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004912e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1705: #0: ffff8881d6765590 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000045d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 5 locks held by kworker/1:3/2754: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881af007dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5c43d80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5c43d80 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881d0743d80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881d0743d80 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881c5d22c10 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881c5d22c10 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 3 locks held by kworker/0:4/2760: #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881da0288a8 ((wq_completion)events){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881af397dd0 ((work_completion)(&fw_work->work)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5c47900 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5c47900 (&dev->mutex){....}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1077 [inline] #2: ffff8881d5c47900 (&dev->mutex){....}, at: ath9k_hif_usb_firmware_cb+0x37c/0x500 drivers/net/wireless/ath/ath9k/hif_usb.c:1210 5 locks held by kworker/0:5/2769: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881ae967dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5d0e800 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5d0e800 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881ae6f3500 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881ae6f3500 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881ceef8a10 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881ceef8a10 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 5 locks held by kworker/1:5/2882: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881cf3cfdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5ce3500 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5ce3500 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881c20a1b80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881c20a1b80 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881c20a2c10 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881c20a2c10 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 5 locks held by kworker/1:6/2893: #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8881d91ad028 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: ffff8881d2c67dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: ffff8881d5ce7080 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #2: ffff8881d5ce7080 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: ffff8881cd04bd80 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #3: ffff8881cd04bd80 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: ffff8881cd860a10 (&dev->mutex){....}, at: device_lock include/linux/device.h:1462 [inline] #4: ffff8881cd860a10 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x55/0x96 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1c7 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9a4/0xe50 kernel/hung_task.c:289 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0x28/0x2e0 arch/x86/kernel/process.c:580