ath9k: recover ar9380 chips from rare stuck state
In the experiment with Azimuth ADEPT-n testbed where the APs transmit
power was reduced to 25% and the signal strength was futher attenuated
by 20dB and induced a path loss of ~7dB, the station was reporting
beacon losses and the following issue were observed.
* rx clear is stuck at low for more than 300ms
* dcu chain and complete state is stuck at one of the hang signature
This patch triggers the hang detection logic that recovers the chip
from any of the above conditions. As the issue was originally reported
in ChromeOs with AR9382 chips, this detection logic is enabled only for
AR9380/2 chips.
Cc: Paul Stewart <pstew@google.com>
Reported-by: Gary Morain <gmorain@google.com>
Signed-off-by: Rajkumar Manoharan <rmanohar@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 8c84049..0792d87 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -430,6 +430,8 @@
void ath_reset_work(struct work_struct *work);
void ath_hw_check(struct work_struct *work);
void ath_hw_pll_work(struct work_struct *work);
+void ath_rx_poll(unsigned long data);
+void ath_start_rx_poll(struct ath_softc *sc, u8 nbeacon);
void ath_paprd_calibrate(struct work_struct *work);
void ath_ani_calibrate(unsigned long data);
void ath_start_ani(struct ath_common *common);
@@ -670,6 +672,7 @@
struct ath_beacon_config cur_beacon_conf;
struct delayed_work tx_complete_work;
struct delayed_work hw_pll_work;
+ struct timer_list rx_poll_timer;
#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
struct ath_btcoex btcoex;
diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index 64fcfad..2d47f74 100644
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -174,6 +174,7 @@
RESET_TYPE_TX_ERROR,
RESET_TYPE_TX_HANG,
RESET_TYPE_PLL_HANG,
+ RESET_TYPE_MAC_HANG,
__RESET_TYPE_MAX
};
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 6c69e4e..d1345a8 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1491,11 +1491,84 @@
}
}
+static bool ath9k_hw_check_dcs(u32 dma_dbg, u32 num_dcu_states,
+ int *hang_state, int *hang_pos)
+{
+ static u32 dcu_chain_state[] = {5, 6, 9}; /* DCU chain stuck states */
+ u32 chain_state, dcs_pos, i;
+
+ for (dcs_pos = 0; dcs_pos < num_dcu_states; dcs_pos++) {
+ chain_state = (dma_dbg >> (5 * dcs_pos)) & 0x1f;
+ for (i = 0; i < 3; i++) {
+ if (chain_state == dcu_chain_state[i]) {
+ *hang_state = chain_state;
+ *hang_pos = dcs_pos;
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+#define DCU_COMPLETE_STATE 1
+#define DCU_COMPLETE_STATE_MASK 0x3
+#define NUM_STATUS_READS 50
+static bool ath9k_hw_detect_mac_hang(struct ath_hw *ah)
+{
+ u32 chain_state, comp_state, dcs_reg = AR_DMADBG_4;
+ u32 i, hang_pos, hang_state, num_state = 6;
+
+ comp_state = REG_READ(ah, AR_DMADBG_6);
+
+ if ((comp_state & DCU_COMPLETE_STATE_MASK) != DCU_COMPLETE_STATE) {
+ ath_dbg(ath9k_hw_common(ah), RESET,
+ "MAC Hang signature not found at DCU complete\n");
+ return false;
+ }
+
+ chain_state = REG_READ(ah, dcs_reg);
+ if (ath9k_hw_check_dcs(chain_state, num_state, &hang_state, &hang_pos))
+ goto hang_check_iter;
+
+ dcs_reg = AR_DMADBG_5;
+ num_state = 4;
+ chain_state = REG_READ(ah, dcs_reg);
+ if (ath9k_hw_check_dcs(chain_state, num_state, &hang_state, &hang_pos))
+ goto hang_check_iter;
+
+ ath_dbg(ath9k_hw_common(ah), RESET,
+ "MAC Hang signature 1 not found\n");
+ return false;
+
+hang_check_iter:
+ ath_dbg(ath9k_hw_common(ah), RESET,
+ "DCU registers: chain %08x complete %08x Hang: state %d pos %d\n",
+ chain_state, comp_state, hang_state, hang_pos);
+
+ for (i = 0; i < NUM_STATUS_READS; i++) {
+ chain_state = REG_READ(ah, dcs_reg);
+ chain_state = (chain_state >> (5 * hang_pos)) & 0x1f;
+ comp_state = REG_READ(ah, AR_DMADBG_6);
+
+ if (((comp_state & DCU_COMPLETE_STATE_MASK) !=
+ DCU_COMPLETE_STATE) ||
+ (chain_state != hang_state))
+ return false;
+ }
+
+ ath_dbg(ath9k_hw_common(ah), RESET, "MAC Hang signature 1 found\n");
+
+ return true;
+}
+
bool ath9k_hw_check_alive(struct ath_hw *ah)
{
int count = 50;
u32 reg;
+ if (AR_SREV_9300(ah))
+ return !ath9k_hw_detect_mac_hang(ah);
+
if (AR_SREV_9285_12_OR_LATER(ah))
return true;
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index cb00645..b8f3423 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -779,6 +779,7 @@
goto error_world;
}
+ setup_timer(&sc->rx_poll_timer, ath_rx_poll, (unsigned long)sc);
sc->last_rssi = ATH_RSSI_DUMMY_MARKER;
ath_init_leds(sc);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 3879485..eeea81b 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -243,6 +243,7 @@
sc->hw_busy_count = 0;
del_timer_sync(&common->ani.timer);
+ del_timer_sync(&sc->rx_poll_timer);
ath9k_debug_samp_bb_mac(sc);
ath9k_hw_disable_interrupts(ah);
@@ -284,6 +285,7 @@
ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0);
ieee80211_queue_delayed_work(sc->hw, &sc->hw_pll_work, HZ/2);
+ ath_start_rx_poll(sc, 3);
if (!common->disable_ani)
ath_start_ani(common);
}
@@ -914,10 +916,19 @@
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
unsigned long flags;
int busy;
+ u8 is_alive, nbeacon = 1;
ath9k_ps_wakeup(sc);
- if (ath9k_hw_check_alive(sc->sc_ah))
+ is_alive = ath9k_hw_check_alive(sc->sc_ah);
+
+ if (is_alive && !AR_SREV_9300(sc->sc_ah))
goto out;
+ 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);
+ goto sched_reset;
+ }
spin_lock_irqsave(&common->cc_lock, flags);
busy = ath_update_survey_stats(sc);
@@ -928,12 +939,18 @@
if (busy >= 99) {
if (++sc->hw_busy_count >= 3) {
RESET_STAT_INC(sc, RESET_TYPE_BB_HANG);
- ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ goto sched_reset;
}
-
- } else if (busy >= 0)
+ } else if (busy >= 0) {
sc->hw_busy_count = 0;
+ nbeacon = 3;
+ }
+ ath_start_rx_poll(sc, nbeacon);
+ goto out;
+
+sched_reset:
+ ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
out:
ath9k_ps_restore(sc);
}
@@ -1153,6 +1170,7 @@
mutex_lock(&sc->mutex);
ath_cancel_work(sc);
+ del_timer_sync(&sc->rx_poll_timer);
if (sc->sc_flags & SC_OP_INVALID) {
ath_dbg(common, ANY, "Device not present\n");
@@ -1385,6 +1403,24 @@
}
}
+void ath_start_rx_poll(struct ath_softc *sc, u8 nbeacon)
+{
+ if (!AR_SREV_9300(sc->sc_ah))
+ return;
+
+ if (!(sc->sc_flags & SC_OP_PRIM_STA_VIF))
+ return;
+
+ mod_timer(&sc->rx_poll_timer, jiffies + msecs_to_jiffies
+ (nbeacon * sc->cur_beacon_conf.beacon_interval));
+}
+
+void ath_rx_poll(unsigned long data)
+{
+ struct ath_softc *sc = (struct ath_softc *)data;
+
+ ieee80211_queue_work(sc->hw, &sc->hw_check_work);
+}
static int ath9k_add_interface(struct ieee80211_hw *hw,
struct ieee80211_vif *vif)
@@ -1906,6 +1942,8 @@
sc->last_rssi = ATH_RSSI_DUMMY_MARKER;
sc->sc_ah->stats.avgbrssi = ATH_RSSI_DUMMY_MARKER;
+ ath_start_rx_poll(sc, 3);
+
if (!common->disable_ani) {
sc->sc_flags |= SC_OP_ANI_RUN;
ath_start_ani(common);
@@ -1945,6 +1983,7 @@
/* Stop ANI */
sc->sc_flags &= ~SC_OP_ANI_RUN;
del_timer_sync(&common->ani.timer);
+ del_timer_sync(&sc->rx_poll_timer);
memset(&sc->caldata, 0, sizeof(sc->caldata));
}
}
@@ -1988,6 +2027,7 @@
} else {
sc->sc_flags &= ~SC_OP_ANI_RUN;
del_timer_sync(&common->ani.timer);
+ del_timer_sync(&sc->rx_poll_timer);
}
}
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 1c4583c..8588017 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -1855,6 +1855,10 @@
if (retval)
goto requeue_drop_frag;
+ if (rs.is_mybeacon) {
+ sc->hw_busy_count = 0;
+ ath_start_rx_poll(sc, 3);
+ }
/* Ensure we always have an skb to requeue once we are done
* processing the current buffer's skb */
requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);