Seen while stress testing bind/unbind.

[149280.524297] INFO: task kworker/2:0:5802 blocked for more than 120 seconds.
[149280.531321]       Not tainted 4.4.52 #620
[149280.535516] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[149280.544152] kworker/2:0     D ffffffc000204ff0     0  5802      2 0x00000000
[149280.551544] Workqueue: pm pm_runtime_work
[149280.555766] Call trace:
[149280.558373] [<ffffffc000204ff0>] __switch_to+0x9c/0xa8
[149280.563655] [<ffffffc00093ab80>] __schedule+0x504/0x740
[149280.569018] [<ffffffc00093ae44>] schedule+0x88/0xa8
[149280.574045] [<ffffffc00093df98>] schedule_timeout+0x44/0x27c
[149280.579835] [<ffffffc00093ba9c>] wait_for_common+0xf8/0x198
[149280.585540] [<ffffffc00093bb64>] wait_for_completion+0x28/0x34
[149280.591528] [<ffffffc0006a36e0>] xhci_stop_device.constprop.12+0x118/0x168
[149280.598652] [<ffffffc0006a4574>] xhci_hub_control+0xc00/0x1198
[149280.604647] [<ffffffc00066a690>] usb_hcd_submit_urb+0x5d8/0x804
[149280.610759] [<ffffffc00066b9cc>] usb_submit_urb+0x3f0/0x410
[149280.616589] [<ffffffc00066c188>] usb_start_wait_urb+0x68/0xec
[149280.625117] [<ffffffc00066c2d8>] usb_control_msg+0xcc/0x114
[149280.631010] [<ffffffc0006618cc>] set_port_feature+0x5c/0x74
[149280.636686] [<ffffffc000665e60>] usb_port_suspend+0x184/0x258
[149280.642527] [<ffffffc000679500>] generic_suspend+0x4c/0x60
[149280.648104] [<ffffffc00066f68c>] usb_suspend_both+0x158/0x1b8
[149280.653973] [<ffffffc000670508>] usb_runtime_suspend+0x3c/0x88
[149280.659898] [<ffffffc00060c358>] __rpm_callback+0x48/0x7c
[149280.665398] [<ffffffc00060c410>] rpm_callback+0x84/0xa4
[149280.670723] [<ffffffc00060cc04>] rpm_suspend+0x2b4/0x4e4
[149280.676132] [<ffffffc00060dd58>] __pm_runtime_suspend+0x60/0xac
[149280.682277] [<ffffffc0006705b4>] usb_runtime_idle+0x30/0x40
[149280.688109] [<ffffffc00060c358>] __rpm_callback+0x48/0x7c
[149280.693615] [<ffffffc00060d104>] rpm_idle+0x218/0x318
[149280.698760] [<ffffffc00060de90>] pm_runtime_work+0x6c/0xa0
[149280.704344] [<ffffffc0002395dc>] process_one_work+0x26c/0x420
[149280.710185] [<ffffffc00023a4f0>] worker_thread+0x2fc/0x424
[149280.715765] [<ffffffc00023f840>] kthread+0x10c/0x114
[149280.720833] [<ffffffc000203dd0>] ret_from_fork+0x10/0x40
...
[149280.910079] basename        D ffffffc000204ff0     0  5157   3329 0x00400008
[149280.917253] Call trace:
[149280.919815] [<ffffffc000204ff0>] __switch_to+0x9c/0xa8
[149280.925044] [<ffffffc00093ab80>] __schedule+0x504/0x740
[149280.930360] [<ffffffc00093ae44>] schedule+0x88/0xa8
[149280.935331] [<ffffffc00060d590>] rpm_resume+0x2e0/0x52c
[149280.940652] [<ffffffc00060db10>] pm_runtime_forbid+0x58/0x6c
[149280.946399] [<ffffffc00066f250>] usb_disable_autosuspend+0x20/0x2c
[149280.952679] [<ffffffc00066526c>] usb_disconnect+0x98/0x1e0
[149280.958263] [<ffffffc00066525c>] usb_disconnect+0x88/0x1e0
[149280.963853] [<ffffffc0006692cc>] usb_remove_hcd+0xc8/0x1e4
[149280.969434] [<ffffffc0006a6a20>] xhci_plat_remove+0x78/0xb4
[149280.975104] [<ffffffc00060379c>] platform_drv_remove+0x30/0x50
[149280.981019] [<ffffffc000601b2c>] __device_release_driver+0xb4/0x114
[149280.987386] [<ffffffc000601bb8>] device_release_driver+0x2c/0x40
[149280.993481] [<ffffffc000600c5c>] bus_remove_device+0x110/0x128
[149280.999423] [<ffffffc0005fdbb4>] device_del+0x164/0x1fc
[149281.004742] [<ffffffc000603cd8>] platform_device_del+0x24/0x84
[149281.010672] [<ffffffc000603d58>] platform_device_unregister+0x20/0x34
[149281.017201] [<ffffffc00067f4dc>] dwc3_host_exit+0x60/0x6c
[149281.022703] [<ffffffc00067c8a0>] dwc3_remove+0x78/0xcc
[149281.027931] [<ffffffc00060379c>] platform_drv_remove+0x30/0x50
[149281.033865] [<ffffffc000601b2c>] __device_release_driver+0xb4/0x114
[149281.040226] [<ffffffc000601bb8>] device_release_driver+0x2c/0x40
[149281.046327] [<ffffffc000600c5c>] bus_remove_device+0x110/0x128
[149281.052251] [<ffffffc0005fdbb4>] device_del+0x164/0x1fc
[149281.057575] [<ffffffc000603cd8>] platform_device_del+0x24/0x84
[149281.063490] [<ffffffc000603d58>] platform_device_unregister+0x20/0x34
[149281.070033] [<ffffffc00078973c>] of_platform_device_destroy+0x60/0xb4
[149281.076557] [<ffffffc0005fce24>] device_for_each_child+0x74/0xa4
[149281.082651] [<ffffffc0007896c0>] of_platform_depopulate+0x3c/0x58
[149281.088831] [<ffffffc000680158>] dwc3_rockchip_remove+0x68/0xd0
[149281.094843] [<ffffffc00060379c>] platform_drv_remove+0x30/0x50
[149281.100756] [<ffffffc000601b2c>] __device_release_driver+0xb4/0x114
[149281.107115] [<ffffffc000601bb8>] device_release_driver+0x2c/0x40
[149281.113202] [<ffffffc000600570>] unbind_store+0x70/0xac
[149281.118533] [<ffffffc0005ff468>] drv_attr_store+0x4c/0x58
[149281.124017] [<ffffffc0003d8870>] sysfs_kf_write+0x5c/0x68
[149281.129529] [<ffffffc0003d7938>] kernfs_fop_write+0x118/0x170
[149281.135361] [<ffffffc0003661d8>] __vfs_write+0x58/0x11c
[149281.140675] [<ffffffc000366bf0>] vfs_write+0xbc/0x154
[149281.145809] [<ffffffc0003674ec>] SyS_write+0x64/0xb4
[149281.150867] [<ffffffc000203e34>] el0_svc_naked+0x24/0x28