--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -1677,6 +1677,50 @@ static const struct file_operations fops
 };
 
 
+static ssize_t read_file_diag(struct file *file, char __user *user_buf,
+			     size_t count, loff_t *ppos)
+{
+	struct ath_softc *sc = file->private_data;
+	struct ath_hw *ah = sc->sc_ah;
+	char buf[32];
+	unsigned int len;
+
+	len = sprintf(buf, "0x%08lx\n", ah->diag);
+	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t write_file_diag(struct file *file, const char __user *user_buf,
+			     size_t count, loff_t *ppos)
+{
+	struct ath_softc *sc = file->private_data;
+	struct ath_hw *ah = sc->sc_ah;
+	unsigned long diag;
+	char buf[32];
+	ssize_t len;
+
+	len = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, user_buf, len))
+		return -EFAULT;
+
+	buf[len] = '\0';
+	if (strict_strtoul(buf, 0, &diag))
+		return -EINVAL;
+
+	ah->diag = diag;
+	ath9k_hw_update_diag(ah);
+
+	return count;
+}
+
+static const struct file_operations fops_diag = {
+	.read = read_file_diag,
+	.write = write_file_diag,
+	.open = simple_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
+
 int ath9k_init_debug(struct ath_hw *ah)
 {
 	struct ath_common *common = ath9k_hw_common(ah);
@@ -1759,5 +1803,8 @@ int ath9k_init_debug(struct ath_hw *ah)
 	debugfs_create_file("chanbw", S_IRUSR | S_IWUSR, sc->debug.debugfs_phy,
 			    sc, &fops_chanbw);
 
+	debugfs_create_file("diag", S_IRUSR | S_IWUSR, sc->debug.debugfs_phy,
+			    sc, &fops_diag);
+
 	return 0;
 }
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -498,6 +498,12 @@ enum {
 	ATH9K_RESET_COLD,
 };
 
+enum {
+	ATH_DIAG_DISABLE_RX,
+	ATH_DIAG_DISABLE_TX,
+	ATH_DIAG_TRIGGER_ERROR,
+};
+
 struct ath9k_hw_version {
 	u32 magic;
 	u16 devid;
@@ -741,6 +747,8 @@ struct ath_hw {
 	u32 rfkill_polarity;
 	u32 ah_flags;
 
+	unsigned long diag;
+
 	bool htc_reset_init;
 
 	enum nl80211_iftype opmode;
@@ -1007,6 +1015,7 @@ void ath9k_hw_set_sta_beacon_timers(stru
 bool ath9k_hw_check_alive(struct ath_hw *ah);
 
 bool ath9k_hw_setpower(struct ath_hw *ah, enum ath9k_power_mode mode);
+void ath9k_hw_update_diag(struct ath_hw *ah);
 
 #ifdef CONFIG_ATH9K_DEBUGFS
 void ath9k_debug_sync_cause(struct ath_common *common, u32 sync_cause);
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1751,6 +1751,20 @@ fail:
 	return -EINVAL;
 }
 
+void ath9k_hw_update_diag(struct ath_hw *ah)
+{
+	if (test_bit(ATH_DIAG_DISABLE_RX, &ah->diag))
+		REG_SET_BIT(ah, AR_DIAG_SW, AR_DIAG_RX_DIS);
+	else
+		REG_CLR_BIT(ah, AR_DIAG_SW, AR_DIAG_RX_DIS);
+
+	if (test_bit(ATH_DIAG_DISABLE_TX, &ah->diag))
+		REG_SET_BIT(ah, AR_DIAG_SW, AR_DIAG_LOOP_BACK);
+	else
+		REG_CLR_BIT(ah, AR_DIAG_SW, AR_DIAG_LOOP_BACK);
+}
+EXPORT_SYMBOL(ath9k_hw_update_diag);
+
 int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
 		   struct ath9k_hw_cal_data *caldata, bool fastcc)
 {
@@ -2028,6 +2042,7 @@ int ath9k_hw_reset(struct ath_hw *ah, st
 	}
 
 	ath9k_hw_apply_gpio_override(ah);
+	ath9k_hw_update_diag(ah);
 
 	return 0;
 }
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -469,6 +469,11 @@ irqreturn_t ath_isr(int irq, void *dev)
 	ath9k_hw_getisr(ah, &status);	/* NB: clears ISR too */
 	status &= ah->imask;	/* discard unasked-for bits */
 
+	if (test_bit(ATH_DIAG_TRIGGER_ERROR, &ah->diag)) {
+		status |= ATH9K_INT_FATAL;
+		clear_bit(ATH_DIAG_TRIGGER_ERROR, &ah->diag);
+	}
+
 	/*
 	 * If there are no status bits set, then this interrupt was not
 	 * for me (should have been caught above).
