ath9k: Fix MCI reset in BT cal_req

This patch reverts the commit "ath9k_hw: Wait BT calibration to complete"
and bail out from MCI interrupt routine for chip reset. The above commit
stalls the WLAN TCP traffic while bringing up and down the BT interface
iteratively. Fixing this properly by queueing up chip reset and bailing
out properly from tasklet routine.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9003_mci.c

@@ -714,7 +714,6 @@ bool ar9003_mci_start_reset(struct ath_hw *ah, struct ath9k_channel *chan)
 
 	return true;
 }
-EXPORT_SYMBOL(ar9003_mci_start_reset);
 
 int ar9003_mci_end_reset(struct ath_hw *ah, struct ath9k_channel *chan,
 			 struct ath9k_hw_cal_data *caldata)

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

@@ -837,6 +837,9 @@ static ssize_t read_file_reset(struct file *file, char __user *user_buf,
 	len += snprintf(buf + len, sizeof(buf) - len,
 			"%17s: %2d\n", "PLL RX Hang",
 			sc->debug.stats.reset[RESET_TYPE_PLL_HANG]);
+	len += snprintf(buf + len, sizeof(buf) - len,
+			"%17s: %2d\n", "MCI Reset",
+			sc->debug.stats.reset[RESET_TYPE_MCI]);
 
 	if (len > sizeof(buf))
 		len = sizeof(buf);

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

@@ -41,6 +41,7 @@ enum ath_reset_type {
 	RESET_TYPE_PLL_HANG,
 	RESET_TYPE_MAC_HANG,
 	RESET_TYPE_BEACON_STUCK,
+	RESET_TYPE_MCI,
 	__RESET_TYPE_MAX
 };
 

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

@@ -207,23 +207,6 @@ skip_tuning:
 	ath9k_btcoex_timer_resume(sc);
 }
 
-static void ath_mci_wait_btcal_done(struct ath_softc *sc)
-{
-	struct ath_hw *ah = sc->sc_ah;
-
-	/* Stop tx & rx */
-	ieee80211_stop_queues(sc->hw);
-	ath_stoprecv(sc);
-	ath_drain_all_txq(sc, false);
-
-	/* Wait for cal done */
-	ar9003_mci_start_reset(ah, ah->curchan);
-
-	/* Resume tx & rx */
-	ath_startrecv(sc);
-	ieee80211_wake_queues(sc->hw);
-}
-
 static void ath_mci_cal_msg(struct ath_softc *sc, u8 opcode, u8 *rx_payload)
 {
 	struct ath_hw *ah = sc->sc_ah;
@@ -235,7 +218,7 @@ static void ath_mci_cal_msg(struct ath_softc *sc, u8 opcode, u8 *rx_payload)
 	case MCI_GPM_BT_CAL_REQ:
 		if (mci_hw->bt_state == MCI_BT_AWAKE) {
 			mci_hw->bt_state = MCI_BT_CAL_START;
-			ath_mci_wait_btcal_done(sc);
+			ath9k_queue_reset(sc, RESET_TYPE_MCI);
 		}
 		ath_dbg(common, MCI, "MCI State : %d\n", mci_hw->bt_state);
 		break;
@@ -578,6 +561,8 @@ void ath_mci_intr(struct ath_softc *sc)
 		mci_int_rxmsg &= ~AR_MCI_INTERRUPT_RX_MSG_GPM;
 
 		while (more_data == MCI_GPM_MORE) {
+			if (test_bit(SC_OP_HW_RESET, &sc->sc_flags))
+				return;
 
 			pgpm = mci->gpm_buf.bf_addr;
 			offset = ar9003_mci_get_next_gpm_offset(ah, false,