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/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);
}
}