From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxxxx>
BUG: soft lockup - CPU#0 stuck for 22s! [hostapd:965]
CPU: 0 PID: 965 Comm: hostapd Not tainted 3.14.0 #1
task: 82e29c40 ti: 82fb2000 task.ti: 82fb2000
$ 0 : 00000000 00000000 83281f90 00004018
$ 4 : 832a0010 b810403c 00004030 00000600
$ 8 : 8036a980 ffd23940 00000000 00000000
$12 : 00000060 00000007 00000000 0000000c
$16 : 832a0010 00023f40 00000002 00000000
$20 : 832a0010 832a0298 832ba994 832bb83c
$24 : 00000002 800aa2d4
$28 : 82fb2000 82fb3c08 832bbf0c 8339edc4
Hi : 00000006
Lo : 009b9500
epc : 8339ede0 ath9k_hw_enable_interrupts+0xf8/0x194 [ath9k_hw]
Not tainted
ra : 8339edc4 ath9k_hw_enable_interrupts+0xdc/0x194 [ath9k_hw]
Status: 1000fc03 KERNEL EXL IE
Cause : 5080d400
PrId : 00019374 (MIPS 24Kc)
Kernel panic - not syncing: softlockup: hung tasks
The original intention of commit e3f31175a3("ath9k: fix race condition
in irq processing during hardware reset") is to avoid the IRQ storms,it
disabled the IRQ entirely for the duration of the reset, but it introducted
a new IRQ storms in handle_level_irq() when call ath9k_hw_enable_interrupts(),
meanwhile the irq is disabled by disable_irq(). Remove disable_irq/enable_irq
paire, instead of diabling tasklet to re-enable IRQ during the reset.
Signed-off-by: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/main.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index b0badef..06560b5 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -285,7 +285,6 @@ static int ath_reset_internal(struct ath_softc *sc, struct ath9k_channel *hchan)
__ath_cancel_work(sc);
- disable_irq(sc->irq);
tasklet_disable(&sc->intr_tq);
tasklet_disable(&sc->bcon_tasklet);
spin_lock_bh(&sc->sc_pcu_lock);
@@ -332,7 +331,6 @@ static int ath_reset_internal(struct ath_softc *sc, struct ath9k_channel *hchan)
r = -EIO;
out:
- enable_irq(sc->irq);
spin_unlock_bh(&sc->sc_pcu_lock);
tasklet_enable(&sc->bcon_tasklet);
tasklet_enable(&sc->intr_tq);
@@ -475,7 +473,8 @@ void ath9k_tasklet(unsigned long data)
ath9k_btcoex_handle_interrupt(sc, status);
/* re-enable hardware interrupt */
- ath9k_hw_enable_interrupts(ah);
+ if (!test_bit(ATH_OP_HW_RESET, &common->op_flags))
+ ath9k_hw_enable_interrupts(ah);
out:
spin_unlock(&sc->sc_pcu_lock);
ath9k_ps_restore(sc);
@@ -603,8 +602,8 @@ int ath_reset(struct ath_softc *sc, struct ath9k_channel *hchan)
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
int r;
- ath9k_hw_kill_interrupts(sc->sc_ah);
set_bit(ATH_OP_HW_RESET, &common->op_flags);
+ ath9k_hw_kill_interrupts(sc->sc_ah);
ath9k_ps_wakeup(sc);
r = ath_reset_internal(sc, hchan);
@@ -624,8 +623,8 @@ void ath9k_queue_reset(struct ath_softc *sc, enum ath_reset_type type)
#ifdef CONFIG_ATH9K_DEBUGFS
RESET_STAT_INC(sc, type);
#endif
- ath9k_hw_kill_interrupts(sc->sc_ah);
set_bit(ATH_OP_HW_RESET, &common->op_flags);
+ ath9k_hw_kill_interrupts(sc->sc_ah);
ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
}
--
1.9.1
--
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