ath9k: Fix race in reset-work usage
Using work_pending() to defer certain operations when
a HW-reset work has been queued is racy since the check
would return false when the work item is actually in
execution. Use SC_OP_HW_RESET instead to fix this race.
Also, unify the reset debug statistics maintenance.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index c8af0db..b09285c 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -452,6 +452,7 @@
void ath_check_ani(struct ath_softc *sc);
int ath_update_survey_stats(struct ath_softc *sc);
void ath_update_survey_nf(struct ath_softc *sc, int channel);
+void ath9k_queue_reset(struct ath_softc *sc, enum ath_reset_type type);
/**********/
/* BTCOEX */
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 006ae99d..76f07d8 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -317,11 +317,12 @@
bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
int slot;
- if (work_pending(&sc->hw_reset_work)) {
+ if (test_bit(SC_OP_HW_RESET, &sc->sc_flags)) {
ath_dbg(common, RESET,
"reset work is pending, skip beaconing now\n");
return;
}
+
/*
* Check if the previous beacon has gone out. If
* not don't try to post another, skip this period
@@ -345,7 +346,7 @@
} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
ath_dbg(common, BSTUCK, "beacon is officially stuck\n");
sc->beacon.bmisscnt = 0;
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, RESET_TYPE_BEACON_STUCK);
}
return;
diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index d0f851c..8b9d080 100644
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -32,6 +32,19 @@
#define RESET_STAT_INC(sc, type) do { } while (0)
#endif
+enum ath_reset_type {
+ RESET_TYPE_BB_HANG,
+ RESET_TYPE_BB_WATCHDOG,
+ RESET_TYPE_FATAL_INT,
+ RESET_TYPE_TX_ERROR,
+ RESET_TYPE_TX_HANG,
+ RESET_TYPE_PLL_HANG,
+ RESET_TYPE_MAC_HANG,
+ RESET_TYPE_BEACON_STUCK,
+ RESET_TYPE_MCI,
+ __RESET_TYPE_MAX
+};
+
#ifdef CONFIG_ATH9K_DEBUGFS
/**
@@ -209,17 +222,6 @@
u32 rx_frags;
};
-enum ath_reset_type {
- RESET_TYPE_BB_HANG,
- RESET_TYPE_BB_WATCHDOG,
- RESET_TYPE_FATAL_INT,
- RESET_TYPE_TX_ERROR,
- RESET_TYPE_TX_HANG,
- RESET_TYPE_PLL_HANG,
- RESET_TYPE_MAC_HANG,
- __RESET_TYPE_MAX
-};
-
struct ath_stats {
struct ath_interrupt_stats istats;
struct ath_tx_stats txstats[ATH9K_NUM_TX_QUEUES];
diff --git a/drivers/net/wireless/ath/ath9k/link.c b/drivers/net/wireless/ath/ath9k/link.c
index 42fc0a3..d4549e9 100644
--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c
@@ -50,8 +50,7 @@
if (needreset) {
ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
"tx hung, resetting the chip\n");
- RESET_STAT_INC(sc, RESET_TYPE_TX_HANG);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, RESET_TYPE_TX_HANG);
return;
}
@@ -69,6 +68,7 @@
unsigned long flags;
int busy;
u8 is_alive, nbeacon = 1;
+ enum ath_reset_type type;
ath9k_ps_wakeup(sc);
is_alive = ath9k_hw_check_alive(sc->sc_ah);
@@ -78,7 +78,7 @@
else if (!is_alive && AR_SREV_9300(sc->sc_ah)) {
ath_dbg(common, RESET,
"DCU stuck is detected. Schedule chip reset\n");
- RESET_STAT_INC(sc, RESET_TYPE_MAC_HANG);
+ type = RESET_TYPE_MAC_HANG;
goto sched_reset;
}
@@ -90,7 +90,7 @@
busy, sc->hw_busy_count + 1);
if (busy >= 99) {
if (++sc->hw_busy_count >= 3) {
- RESET_STAT_INC(sc, RESET_TYPE_BB_HANG);
+ type = RESET_TYPE_BB_HANG;
goto sched_reset;
}
} else if (busy >= 0) {
@@ -102,7 +102,7 @@
goto out;
sched_reset:
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, type);
out:
ath9k_ps_restore(sc);
}
@@ -119,8 +119,7 @@
count++;
if (count == 3) {
ath_dbg(common, RESET, "PLL WAR, resetting the chip\n");
- RESET_STAT_INC(sc, RESET_TYPE_PLL_HANG);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, RESET_TYPE_PLL_HANG);
count = 0;
return true;
}
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 1caaf92..6049d8b 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -363,6 +363,7 @@
struct ath_softc *sc = (struct ath_softc *)data;
struct ath_hw *ah = sc->sc_ah;
struct ath_common *common = ath9k_hw_common(ah);
+ enum ath_reset_type type;
unsigned long flags;
u32 status = sc->intrstatus;
u32 rxmask;
@@ -372,18 +373,13 @@
if ((status & ATH9K_INT_FATAL) ||
(status & ATH9K_INT_BB_WATCHDOG)) {
-#ifdef CONFIG_ATH9K_DEBUGFS
- enum ath_reset_type type;
if (status & ATH9K_INT_FATAL)
type = RESET_TYPE_FATAL_INT;
else
type = RESET_TYPE_BB_WATCHDOG;
- RESET_STAT_INC(sc, type);
-#endif
- set_bit(SC_OP_HW_RESET, &sc->sc_flags);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, type);
goto out;
}
@@ -584,6 +580,15 @@
return r;
}
+void ath9k_queue_reset(struct ath_softc *sc, enum ath_reset_type type)
+{
+#ifdef CONFIG_ATH9K_DEBUGFS
+ RESET_STAT_INC(sc, type);
+#endif
+ set_bit(SC_OP_HW_RESET, &sc->sc_flags);
+ ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+}
+
void ath_reset_work(struct work_struct *work)
{
struct ath_softc *sc = container_of(work, struct ath_softc, hw_reset_work);
diff --git a/drivers/net/wireless/ath/ath9k/mci.c b/drivers/net/wireless/ath/ath9k/mci.c
index 87acff7..fb536e7 100644
--- a/drivers/net/wireless/ath/ath9k/mci.c
+++ b/drivers/net/wireless/ath/ath9k/mci.c
@@ -202,7 +202,7 @@
case MCI_GPM_BT_CAL_REQ:
if (mci_hw->bt_state == MCI_BT_AWAKE) {
ar9003_mci_state(ah, MCI_STATE_SET_BT_CAL_START);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ ath9k_queue_reset(sc, RESET_TYPE_MCI);
}
ath_dbg(common, MCI, "MCI State : %d\n", mci_hw->bt_state);
break;
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 310c95e..2c9da6b 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -589,10 +589,8 @@
rcu_read_unlock();
- if (needreset) {
- RESET_STAT_INC(sc, RESET_TYPE_TX_ERROR);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
- }
+ if (needreset)
+ ath9k_queue_reset(sc, RESET_TYPE_TX_ERROR);
}
static bool ath_lookup_legacy(struct ath_buf *bf)
@@ -1589,7 +1587,8 @@
struct ath_atx_ac *ac, *ac_tmp, *last_ac;
struct ath_atx_tid *tid, *last_tid;
- if (work_pending(&sc->hw_reset_work) || list_empty(&txq->axq_acq) ||
+ if (test_bit(SC_OP_HW_RESET, &sc->sc_flags) ||
+ list_empty(&txq->axq_acq) ||
txq->axq_ampdu_depth >= ATH_AGGR_MIN_QDEPTH)
return;
@@ -2196,7 +2195,7 @@
ath_txq_lock(sc, txq);
for (;;) {
- if (work_pending(&sc->hw_reset_work))
+ if (test_bit(SC_OP_HW_RESET, &sc->sc_flags))
break;
if (list_empty(&txq->axq_q)) {
@@ -2279,7 +2278,7 @@
int status;
for (;;) {
- if (work_pending(&sc->hw_reset_work))
+ if (test_bit(SC_OP_HW_RESET, &sc->sc_flags))
break;
status = ath9k_hw_txprocdesc(ah, NULL, (void *)&ts);
