ath9k_hw: Fix RTT calibration

This patch fixes multiple issues with the current RTT
implementation in ath9k.

* The data that is obtained from the RTT interface registers
  are stored in 31:5 - mask out the extra bits when reading them.

* A history buffer is maintained which is not needed at all.
  Remove this array and just store the baseband data for each
  chain (or bank).

* A 'num_readings' variable was being used to handle the
  last entry. But it was being used in an improper manner, with
  the result that the RTT values were never being written
  to the RTT Interface registers. Fix this by using a simple
  flag.

* Stop baseband operations before programming the calibration values
  to the HW.

* Do not restore RX gain settings as part of RTT.

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

1 files changed, 10 insertions, 40 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_calib.c b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
index a0387a0..9fdd70f 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
@@ -892,34 +892,6 @@ static void ar9003_hw_tx_iq_cal_reload(struct ath_hw *ah)
 		      AR_PHY_RX_IQCAL_CORR_B0_LOOPBACK_IQCORR_EN, 0x1);
 }
 
-static bool ar9003_hw_rtt_restore(struct ath_hw *ah, struct ath9k_channel *chan)
-{
-	struct ath9k_rtt_hist *hist;
-	u32 *table;
-	int i;
-	bool restore;
-
-	if (!ah->caldata)
-		return false;
-
-	hist = &ah->caldata->rtt_hist;
-	if (!hist->num_readings)
-		return false;
-
-	ar9003_hw_rtt_enable(ah);
-	ar9003_hw_rtt_set_mask(ah, 0x00);
-	for (i = 0; i < AR9300_MAX_CHAINS; i++) {
-		if (!(ah->rxchainmask & (1 << i)))
-			continue;
-		table = &hist->table[i][hist->num_readings][0];
-		ar9003_hw_rtt_load_hist(ah, i, table);
-	}
-	restore = ar9003_hw_rtt_force_restore(ah);
-	ar9003_hw_rtt_disable(ah);
-
-	return restore;
-}
-
 static bool ar9003_hw_init_cal(struct ath_hw *ah,
 			       struct ath9k_channel *chan)
 {
@@ -942,9 +914,10 @@ static bool ar9003_hw_init_cal(struct ath_hw *ah,
 		if (!ar9003_hw_rtt_restore(ah, chan))
 			run_rtt_cal = true;
 
-		ath_dbg(common, CALIBRATE, "RTT restore %s\n",
-			run_rtt_cal ? "failed" : "succeed");
+		if (run_rtt_cal)
+			ath_dbg(common, CALIBRATE, "RTT calibration to be done\n");
 	}
+
 	run_agc_cal = run_rtt_cal;
 
 	if (run_rtt_cal) {
@@ -1069,17 +1042,14 @@ skip_tx_iqcal:
 #undef CL_TAB_ENTRY
 
 	if (run_rtt_cal && caldata) {
-		struct ath9k_rtt_hist *hist = &caldata->rtt_hist;
-		if (is_reusable && (hist->num_readings < RTT_HIST_MAX)) {
-			u32 *table;
+		if (is_reusable) {
+			if (!ath9k_hw_rfbus_req(ah))
+				ath_err(ath9k_hw_common(ah),
+					"Could not stop baseband\n");
+			else
+				ar9003_hw_rtt_fill_hist(ah);
 
-			hist->num_readings++;
-			for (i = 0; i < AR9300_MAX_CHAINS; i++) {
-				if (!(ah->rxchainmask & (1 << i)))
-					continue;
-				table = &hist->table[i][hist->num_readings][0];
-				ar9003_hw_rtt_fill_hist(ah, i, table);
-			}
+			ath9k_hw_rfbus_done(ah);
 		}
 
 		ar9003_hw_rtt_disable(ah);