Return-path: Received: from sabertooth02.qualcomm.com ([65.197.215.38]:55633 "EHLO sabertooth02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751607AbbDPCYT (ORCPT ); Wed, 15 Apr 2015 22:24:19 -0400 From: Cc: , , , Miaoqing Pan To: Subject: [PATCH] ath9k: fix soft lockup - CPU stuck Date: Thu, 16 Apr 2015 10:24:10 +0800 Message-ID: <1429151050-22488-1-git-send-email-miaoqing@qca.qualcomm.com> (sfid-20150416_042423_459299_2F2229E6) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Miaoqing Pan 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 --- 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