ath9k_hw: Do fast channel change based on reusable calibration results

Support the fast channel change across band switch only when there
are available of reusable cabliration results. And also observed that
doing agc control calibration on fastcc, sometimes causing calibration
timeout. Hence changing agc control to be run only on full chip reset.

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/ar9003_calib.c b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
index 47f140c..16851cb 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
@@ -1008,8 +1008,7 @@
 	REG_WRITE(ah, AR_PHY_ACTIVE, AR_PHY_ACTIVE_EN);
 
 skip_tx_iqcal:
-
-	if (run_agc_cal) {
+	if (run_agc_cal || !(ah->ah_flags & AH_FASTCC)) {
 		/* Calibrate the AGC */
 		REG_WRITE(ah, AR_PHY_AGC_CONTROL,
 			  REG_READ(ah, AR_PHY_AGC_CONTROL) |
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 0eb0b3b..67831a3 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1445,6 +1445,7 @@
 	ath9k_hw_spur_mitigate_freq(ah, chan);
 
 	if (edma && (band_switch || mode_diff)) {
+		ah->ah_flags |= AH_FASTCC;
 		if (band_switch || ini_reloaded)
 			ah->eep_ops->set_board_values(ah, chan);
 
@@ -1452,6 +1453,7 @@
 
 		if (band_switch || ini_reloaded)
 			ath9k_hw_init_cal(ah, chan);
+		ah->ah_flags &= ~AH_FASTCC;
 	}
 
 	return true;
@@ -1509,6 +1511,7 @@
 	u32 macStaId1;
 	u64 tsf = 0;
 	int i, r;
+	bool allow_fbs = false;
 
 	if (!ath9k_hw_setpower(ah, ATH9K_PM_AWAKE))
 		return -EIO;
@@ -1530,12 +1533,19 @@
 	if (AR_SREV_9280(ah) && common->bus_ops->ath_bus_type == ATH_PCI)
 		bChannelChange = false;
 
+	if (caldata &&
+	    caldata->done_txiqcal_once &&
+	    caldata->done_txclcal_once &&
+	    caldata->rtt_hist.num_readings)
+		allow_fbs = true;
+
 	if (bChannelChange &&
 	    (ah->chip_fullsleep != true) &&
 	    (ah->curchan != NULL) &&
 	    (chan->channel != ah->curchan->channel) &&
-	    ((chan->channelFlags & CHANNEL_ALL) ==
-	     (ah->curchan->channelFlags & CHANNEL_ALL))) {
+	    (allow_fbs ||
+	     ((chan->channelFlags & CHANNEL_ALL) ==
+	      (ah->curchan->channelFlags & CHANNEL_ALL)))) {
 		if (ath9k_hw_channel_change(ah, chan)) {
 			ath9k_hw_loadnf(ah, ah->curchan);
 			ath9k_hw_start_nfcal(ah, true);
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 0f6fc25..156c57a 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -652,6 +652,7 @@
 /* ah_flags */
 #define AH_USE_EEPROM   0x1
 #define AH_UNPLUGGED    0x2 /* The card has been physically removed. */
+#define AH_FASTCC       0x4
 
 struct ath_hw {
 	struct ath_ops reg_ops;