ath9k: enable the baseband watchdog events for AR9003

This enables the baseband watchdog events for the AR9003
family on ath9k. Upon an a baseband watchdog interrupt we reset
the hardware, this should address corner case conditions where
normal operation can stall. Enable ATH_DBG_RESET to be able
to review details of the bb watchdog interrupt once it happens.
If you're curious how often this happens just grep the debugfs
interrupt file.

Cc: Sam Ng <sam.ng@atheros.com>
Cc: Paul Shaw <paul.shaw@atheros.com>
Cc: Don Breslin <don.breslin@atheros.com>
Cc: Cliff Holden <cliff.holden@atheros.com
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -269,6 +269,8 @@ void ath_debug_stat_interrupt(struct ath_softc *sc, enum ath9k_int status)
 			sc->debug.stats.istats.rxlp++;
 		if (status & ATH9K_INT_RXHP)
 			sc->debug.stats.istats.rxhp++;
+		if (status & ATH9K_INT_BB_WATCHDOG)
+			sc->debug.stats.istats.bb_watchdog++;
 	} else {
 		if (status & ATH9K_INT_RX)
 			sc->debug.stats.istats.rxok++;
@@ -319,6 +321,9 @@ static ssize_t read_file_interrupt(struct file *file, char __user *user_buf,
 			"%8s: %10u\n", "RXLP", sc->debug.stats.istats.rxlp);
 		len += snprintf(buf + len, sizeof(buf) - len,
 			"%8s: %10u\n", "RXHP", sc->debug.stats.istats.rxhp);
+		len += snprintf(buf + len, sizeof(buf) - len,
+			"%8s: %10u\n", "WATCHDOG",
+			sc->debug.stats.istats.bb_watchdog);
 	} else {
 		len += snprintf(buf + len, sizeof(buf) - len,
 			"%8s: %10u\n", "RX", sc->debug.stats.istats.rxok);

drivers/net/wireless/ath/ath9k/debug.h

@@ -53,6 +53,7 @@ struct ath_buf;
  * @cabend: RX End of CAB traffic
  * @dtimsync: DTIM sync lossage
  * @dtim: RX Beacon with DTIM
+ * @bb_watchdog: Baseband watchdog
  */
 struct ath_interrupt_stats {
 	u32 total;
@@ -76,6 +77,7 @@ struct ath_interrupt_stats {
 	u32 cabend;
 	u32 dtimsync;
 	u32 dtim;
+	u32 bb_watchdog;
 };
 
 struct ath_rc_stats {

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

@@ -520,6 +520,12 @@ irqreturn_t ath_isr(int irq, void *dev)
 	    !(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)))
 		goto chip_reset;
 
+	if ((ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
+	    (status & ATH9K_INT_BB_WATCHDOG)) {
+		ar9003_hw_bb_watchdog_dbg_info(ah);
+		goto chip_reset;
+	}
+
 	if (status & ATH9K_INT_SWBA)
 		tasklet_schedule(&sc->bcon_tasklet);
 
@@ -1195,7 +1201,9 @@ static int ath9k_start(struct ieee80211_hw *hw)
 		    ATH9K_INT_GLOBAL;
 
 	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
-		ah->imask |= ATH9K_INT_RXHP | ATH9K_INT_RXLP;
+		ah->imask |= ATH9K_INT_RXHP |
+			     ATH9K_INT_RXLP |
+			     ATH9K_INT_BB_WATCHDOG;
 	else
 		ah->imask |= ATH9K_INT_RX;