Re: hung task in mac80211
From: Stefano Brivio <hidden>
Date: 2017-09-06 12:40:29
Also in:
linux-wireless, lkml
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
On Wed, 6 Sep 2017 13:57:47 +0200 Matteo Croce [off-list ref] wrote:
Hi,
I have an hung task on vanilla 4.13 kernel which I haven't on 4.12.
The problem is present both on my AP and on my notebook,
so it seems it affects AP and STA mode as well.
The generated messages are:
INFO: task kworker/u16:6:120 blocked for more than 120 seconds.
Not tainted 4.13.0 #57
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u16:6 D 0 120 2 0x00000000
Workqueue: phy0 ieee80211_ba_session_work [mac80211]
Call Trace:
? __schedule+0x174/0x5b0
? schedule+0x31/0x80
? schedule_preempt_disabled+0x9/0x10
? __mutex_lock.isra.2+0x163/0x480
? select_task_rq_fair+0xb9f/0xc60
? __ieee80211_start_rx_ba_session+0x135/0x4d0 [mac80211]
? __ieee80211_start_rx_ba_session+0x135/0x4d0 [mac80211]This is ugly and maybe wrong, but you could check perhaps...:
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index c92df492e898..bd7512a656f2 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c@@ -320,28 +320,40 @@ void ieee80211_ba_session_work(struct work_struct *work) mutex_lock(&sta->ampdu_mlme.mtx); for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) { - if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired)) + if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired)) { + mutex_unlock(&sta->ampdu_mlme.mtx); ___ieee80211_stop_rx_ba_session( sta, tid, WLAN_BACK_RECIPIENT, WLAN_REASON_QSTA_TIMEOUT, true); + mutex_lock(&sta->ampdu_mlme.mtx); + } if (test_and_clear_bit(tid, - sta->ampdu_mlme.tid_rx_stop_requested)) + sta->ampdu_mlme.tid_rx_stop_requested)) { + mutex_unlock(&sta->ampdu_mlme.mtx); ___ieee80211_stop_rx_ba_session( sta, tid, WLAN_BACK_RECIPIENT, WLAN_REASON_UNSPECIFIED, true); + mutex_lock(&sta->ampdu_mlme.mtx); + } if (test_and_clear_bit(tid, - sta->ampdu_mlme.tid_rx_manage_offl)) + sta->ampdu_mlme.tid_rx_manage_offl)) { + mutex_unlock(&sta->ampdu_mlme.mtx); __ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid, IEEE80211_MAX_AMPDU_BUF, false, true); + mutex_lock(&sta->ampdu_mlme.mtx); + } if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS, - sta->ampdu_mlme.tid_rx_manage_offl)) + sta->ampdu_mlme.tid_rx_manage_offl)) { + mutex_unlock(&sta->ampdu_mlme.mtx); ___ieee80211_stop_rx_ba_session( sta, tid, WLAN_BACK_RECIPIENT, 0, false); + mutex_lock(&sta->ampdu_mlme.mtx); + } spin_lock_bh(&sta->lock);
--
Stefano