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Commit f6b4e4d4 authored by Rajkumar Manoharan's avatar Rajkumar Manoharan Committed by John W. Linville
Browse files

ath9k: Fix locking issue during tx completion 



The received tx status of aggregated frame without BlockAck may
cause deaf state in AR5416 cards. So the driver does a reset to
recover. When this happens, we release the pcu_lock before doing
a reset as ath_rest acquires pcu_lock. This is ugly and also not
atomic. Fixing this addresses the TX DMA failure also.

ath_tx_complete_aggr can be called from different paths which
takes different variants of spin_lock. This patch also addresses
the following warning.

WARNING: at kernel/timer.c:1011 del_timer_sync+0x4e/0x50()
Call Trace:
 <IRQ>  [<ffffffff8104be3a>] warn_slowpath_common+0x7a/0xb0
 [<ffffffff8104be85>] warn_slowpath_null+0x15/0x20
 [<ffffffff8105915e>] del_timer_sync+0x4e/0x50
 [<ffffffffa03726be>] ath_reset+0x3e/0x210 [ath9k]
 [<ffffffff8135cdaf>] ? _raw_spin_unlock_bh+0x1f/0x30
 [<ffffffffa037760a>] ath_tx_complete_aggr.isra.26+0x54a/0xa40 [ath9k]

Signed-off-by: default avatarRajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 428bc8c3

drivers/net/wireless/ath/ath9k/beacon.c

+2 −0
Original line number Diff line number Diff line
@@ -385,7 +385,9 @@ void ath_beacon_tasklet(unsigned long data) 
			ath_dbg(common, ATH_DBG_BSTUCK,

				"beacon is officially stuck\n");

			sc->sc_flags |= SC_OP_TSF_RESET;

			spin_lock(&sc->sc_pcu_lock);

			ath_reset(sc, true);

			spin_unlock(&sc->sc_pcu_lock);

		}



		return;

drivers/net/wireless/ath/ath9k/main.c

+9 −4
Original line number Diff line number Diff line
@@ -617,8 +617,11 @@ void ath_hw_check(struct work_struct *work) 
	ath_dbg(common, ATH_DBG_RESET, "Possible baseband hang, "

		"busy=%d (try %d)\n", busy, sc->hw_busy_count + 1);

	if (busy >= 99) {

		if (++sc->hw_busy_count >= 3)

		if (++sc->hw_busy_count >= 3) {

			spin_lock_bh(&sc->sc_pcu_lock);

			ath_reset(sc, true);

			spin_unlock_bh(&sc->sc_pcu_lock);

		}

	} else if (busy >= 0)

		sc->hw_busy_count = 0;
@@ -637,7 +640,9 @@ static void ath_hw_pll_rx_hang_check(struct ath_softc *sc, u32 pll_sqsum) 
			/* Rx is hung for more than 500ms. Reset it */

			ath_dbg(common, ATH_DBG_RESET,

				"Possible RX hang, resetting");

			spin_lock_bh(&sc->sc_pcu_lock);

			ath_reset(sc, true);

			spin_unlock_bh(&sc->sc_pcu_lock);

			count = 0;

		}

	} else
@@ -674,7 +679,9 @@ void ath9k_tasklet(unsigned long data) 


	if ((status & ATH9K_INT_FATAL) ||

	    (status & ATH9K_INT_BB_WATCHDOG)) {

		spin_lock(&sc->sc_pcu_lock);

		ath_reset(sc, true);

		spin_unlock(&sc->sc_pcu_lock);

		return;

	}
@@ -980,7 +987,6 @@ int ath_reset(struct ath_softc *sc, bool retry_tx) 
	del_timer_sync(&common->ani.timer);



	ath9k_ps_wakeup(sc);

	spin_lock_bh(&sc->sc_pcu_lock);



	ieee80211_stop_queues(hw);
@@ -1023,7 +1029,6 @@ int ath_reset(struct ath_softc *sc, bool retry_tx) 
	}



	ieee80211_wake_queues(hw);

	spin_unlock_bh(&sc->sc_pcu_lock);



	/* Start ANI */

	if (!common->disable_ani)
@@ -2326,9 +2331,9 @@ static void ath9k_flush(struct ieee80211_hw *hw, bool drop) 
	ath9k_ps_wakeup(sc);

	spin_lock_bh(&sc->sc_pcu_lock);

	drain_txq = ath_drain_all_txq(sc, false);

	spin_unlock_bh(&sc->sc_pcu_lock);

	if (!drain_txq)

		ath_reset(sc, false);

	spin_unlock_bh(&sc->sc_pcu_lock);

	ath9k_ps_restore(sc);

	ieee80211_wake_queues(hw);

drivers/net/wireless/ath/ath9k/xmit.c

+3 −4
Original line number Diff line number Diff line
@@ -565,11 +565,8 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq, 


	rcu_read_unlock();



	if (needreset) {

		spin_unlock_bh(&sc->sc_pcu_lock);

	if (needreset)

		ath_reset(sc, false);

		spin_lock_bh(&sc->sc_pcu_lock);

	}

}



static u32 ath_lookup_rate(struct ath_softc *sc, struct ath_buf *bf,
@@ -2169,7 +2166,9 @@ static void ath_tx_complete_poll_work(struct work_struct *work) 
	if (needreset) {

		ath_dbg(ath9k_hw_common(sc->sc_ah), ATH_DBG_RESET,

			"tx hung, resetting the chip\n");

		spin_lock_bh(&sc->sc_pcu_lock);

		ath_reset(sc, true);

		spin_unlock_bh(&sc->sc_pcu_lock);

	}



	ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work,