[  242.604320] INFO: task kworker/u8:2:98 blocked for more than 120 seconds.
[  242.604325]       Not tainted 4.13.0-16-generic #19-Ubuntu
[  242.604327] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  242.604330] kworker/u8:2    D    0    98      2 0x00000000
[  242.604355] Workqueue: phy0 ieee80211_ba_session_work [mac80211]
[  242.604357] Call Trace:
[  242.604363]  __schedule+0x28b/0x890
[  242.604366]  schedule+0x36/0x80
[  242.604368]  schedule_preempt_disabled+0xe/0x10
[  242.604370]  __mutex_lock.isra.2+0x190/0x4e0
[  242.604374]  ? load_balance+0x160/0x9a0
[  242.604377]  __mutex_lock_slowpath+0x13/0x20
[  242.604379]  ? __mutex_lock_slowpath+0x13/0x20
[  242.604381]  mutex_lock+0x2f/0x40
[  242.604398]  __ieee80211_start_rx_ba_session+0x1b7/0x5a0 [mac80211]
[  242.604414]  ieee80211_ba_session_work+0x164/0x250 [mac80211]
[  242.604417]  process_one_work+0x1e7/0x410
[  242.604419]  worker_thread+0x4a/0x410
[  242.604421]  kthread+0x125/0x140
[  242.604423]  ? process_one_work+0x410/0x410
[  242.604425]  ? kthread_create_on_node+0x70/0x70
[  242.604426]  ? kthread_create_on_node+0x70/0x70
[  242.604429]  ret_from_fork+0x25/0x30