Comment 30 for bug 1640547

When heavily loaded I'm seeing a bunch of these USB related kworker thread delay warnings:

[ 5282.423179] INFO: task kworker/136:1:1165 blocked for more than 120 seconds.
[ 5282.423457] Not tainted 4.4.0-47-generic #68-Ubuntu
[ 5282.423498] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5282.423556] kworker/136:1 D 0000000000000000 0 1165 2 0x00000800
[ 5282.423563] Workqueue: events __usb_queue_reset_device
[ 5282.423566] Call Trace:
[ 5282.423570] [c00000793e6c7770] [c000000000015d38] __switch_to+0x1f8/0x350
[ 5282.423574] [c00000793e6c77c0] [c000000000af2ddc] __schedule+0x30c/0x990
[ 5282.423577] [c00000793e6c7890] [c000000000af34a8] schedule+0x48/0xc0
[ 5282.423580] [c00000793e6c78c0] [c000000000823be4] usb_kill_urb+0xc4/0x130
[ 5282.423584] [c00000793e6c7940] [c000000000821988] usb_hcd_flush_endpoint+0x1a8/0x310
[ 5282.423587] [c00000793e6c7a10] [c000000000826310] usb_disable_endpoint+0x80/0x110
[ 5282.423591] [c00000793e6c7a50] [c000000000826410] usb_disable_interface+0x70/0xa0
[ 5282.423594] [c00000793e6c7a90] [c000000000816490] usb_reset_and_verify_device+0x230/0x540
[ 5282.423597] [c00000793e6c7b70] [c000000000816964] usb_reset_device+0x1c4/0x3b0
[ 5282.423601] [c00000793e6c7c10] [c000000000825ef8] __usb_queue_reset_device+0x58/0x90
[ 5282.423604] [c00000793e6c7c50] [c0000000000dd930] process_one_work+0x1e0/0x5a0
[ 5282.423607] [c00000793e6c7ce0] [c0000000000dde84] worker_thread+0x194/0x680
[ 5282.423611] [c00000793e6c7d80] [c0000000000e6980] kthread+0x110/0x130
[ 5282.423615] [c00000793e6c7e30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4