wlcore: Disable interrupts while recovering

In case a recovery is initiated, the FW can no longer be trusted, and
the driver should not handle any new FW events.

Disable the interrupt handler when a recovery is scheduled and balance
it back in the op_stop callback.

Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/ti/wlcore/io.c

@@ -48,6 +48,12 @@ void wlcore_disable_interrupts(struct wl1271 *wl)
 }
 EXPORT_SYMBOL_GPL(wlcore_disable_interrupts);
 
+void wlcore_disable_interrupts_nosync(struct wl1271 *wl)
+{
+	disable_irq_nosync(wl->irq);
+}
+EXPORT_SYMBOL_GPL(wlcore_disable_interrupts_nosync);
+
 void wlcore_enable_interrupts(struct wl1271 *wl)
 {
 	enable_irq(wl->irq);

drivers/net/wireless/ti/wlcore/io.h

@@ -45,6 +45,7 @@
 struct wl1271;
 
 void wlcore_disable_interrupts(struct wl1271 *wl);
+void wlcore_disable_interrupts_nosync(struct wl1271 *wl);
 void wlcore_enable_interrupts(struct wl1271 *wl);
 
 void wl1271_io_reset(struct wl1271 *wl);

drivers/net/wireless/ti/wlcore/main.c

@@ -743,8 +743,11 @@ static void wl1271_fetch_nvs(struct wl1271 *wl)
 
 void wl12xx_queue_recovery_work(struct wl1271 *wl)
 {
-	if (!test_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS, &wl->flags))
+	/* Avoid a recursive recovery */
+	if (!test_and_set_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS, &wl->flags)) {
+		wlcore_disable_interrupts_nosync(wl);
 		ieee80211_queue_work(wl->hw, &wl->recovery_work);
+	}
 }
 
 size_t wl12xx_copy_fwlog(struct wl1271 *wl, u8 *memblock, size_t maxlen)
@@ -848,9 +851,6 @@ static void wl1271_recovery_work(struct work_struct *work)
 	if (wl->state != WL1271_STATE_ON || wl->plt)
 		goto out_unlock;
 
-	/* Avoid a recursive recovery */
-	set_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS, &wl->flags);
-
 	wl12xx_read_fwlog_panic(wl);
 
 	/* change partitions momentarily so we can read the FW pc */
@@ -902,8 +902,6 @@ static void wl1271_recovery_work(struct work_struct *work)
 	mutex_unlock(&wl->mutex);
 	wl1271_op_stop(wl->hw);
 
-	clear_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS, &wl->flags);
-
 	ieee80211_restart_hw(wl->hw);
 
 	/*
@@ -1706,6 +1704,10 @@ static void wl1271_op_stop(struct ieee80211_hw *hw)
 	wlcore_disable_interrupts(wl);
 	mutex_lock(&wl->mutex);
 	if (wl->state == WL1271_STATE_OFF) {
+		if (test_and_clear_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS,
+					&wl->flags))
+			wlcore_enable_interrupts(wl);
+
 		mutex_unlock(&wl->mutex);
 
 		/*
@@ -1737,6 +1739,13 @@ static void wl1271_op_stop(struct ieee80211_hw *hw)
 	mutex_lock(&wl->mutex);
 
 	wl1271_power_off(wl);
+	/*
+	 * In case a recovery was scheduled, interrupts were disabled to avoid
+	 * an interrupt storm. Now that the power is down, it is safe to
+	 * re-enable interrupts to balance the disable depth
+	 */
+	if (test_and_clear_bit(WL1271_FLAG_RECOVERY_IN_PROGRESS, &wl->flags))
+		wlcore_enable_interrupts(wl);
 
 	wl->band = IEEE80211_BAND_2GHZ;