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| author | Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de> | 2016-12-13 18:08:07 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-09 08:32:17 +0100 |
| commit | 71717a3ef900dafe6e9854320491de5b8e972b08 (patch) | |
| tree | 4d4a6bffc26c9640a0ecdc8c2a210cfe8b9946c9 /drivers/net/wireless/ath | |
| parent | de5d62f892c382aae83f454190db55e7be3536d6 (diff) | |
| download | linux-rt-71717a3ef900dafe6e9854320491de5b8e972b08.tar.gz | |
ath9k: do not return early to fix rcu unlocking
commit d1f1c0e289e1bc46cd6873ba6dd6c627f459e7fa upstream.
Starting with commit d94a461d7a7d ("ath9k: use ieee80211_tx_status_noskb
where possible") the driver uses rcu_read_lock() && rcu_read_unlock(), yet on
returning early in ath_tx_edma_tasklet() the unlock is missing leading to stalls
and suspicious RCU usage:
===============================
[ INFO: suspicious RCU usage. ]
4.9.0-rc8 #11 Not tainted
-------------------------------
kernel/rcu/tree.c:705 Illegal idle entry in RCU read-side critical section.!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
1 lock held by swapper/7/0:
#0:
(
rcu_read_lock
){......}
, at:
[<ffffffffa06ed110>] ath_tx_edma_tasklet+0x0/0x450 [ath9k]
stack backtrace:
CPU: 7 PID: 0 Comm: swapper/7 Not tainted 4.9.0-rc8 #11
Hardware name: Acer Aspire V3-571G/VA50_HC_CR, BIOS V2.21 12/16/2013
ffff88025efc3f38 ffffffff8132b1e5 ffff88017ede4540 0000000000000001
ffff88025efc3f68 ffffffff810a25f7 ffff88025efcee60 ffff88017edebdd8
ffff88025eeb5400 0000000000000091 ffff88025efc3f88 ffffffff810c3cd4
Call Trace:
<IRQ>
[<ffffffff8132b1e5>] dump_stack+0x68/0x93
[<ffffffff810a25f7>] lockdep_rcu_suspicious+0xd7/0x110
[<ffffffff810c3cd4>] rcu_eqs_enter_common.constprop.85+0x154/0x200
[<ffffffff810c5a54>] rcu_irq_exit+0x44/0xa0
[<ffffffff81058631>] irq_exit+0x61/0xd0
[<ffffffff81018d25>] do_IRQ+0x65/0x110
[<ffffffff81672189>] common_interrupt+0x89/0x89
<EOI>
[<ffffffff814ffe11>] ? cpuidle_enter_state+0x151/0x200
[<ffffffff814ffee2>] cpuidle_enter+0x12/0x20
[<ffffffff8109a6ae>] call_cpuidle+0x1e/0x40
[<ffffffff8109a8f6>] cpu_startup_entry+0x146/0x220
[<ffffffff810336f8>] start_secondary+0x148/0x170
Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Fixes: d94a461d7a7d ("ath9k: use ieee80211_tx_status_noskb where possible")
Acked-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/wireless/ath')
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/xmit.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index 52bfbb988611..e47286bf378e 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -2787,7 +2787,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc) fifo_list = &txq->txq_fifo[txq->txq_tailidx]; if (list_empty(fifo_list)) { ath_txq_unlock(sc, txq); - return; + break; } bf = list_first_entry(fifo_list, struct ath_buf, list); |