commit 2af242e19f06cfaade7ac8608c9df8af1e0fbb34
author Helmut Schaa <helmut.schaa@googlemail.com> Mon Mar 28 13:32:01 2011 +0200
committer John W. Linville <linville@tuxdriver.com> Mon Apr 04 16:20:02 2011 -0400
tree a7492fb3651ad39cc053e64f0af19469f1958f2d
parent 75faae8b80171b447bfc4bac448308676fb8a663

rt2x00: Don't recalculate HT40 compensation for each rate

Previously the HT40 tx power compensation value was calculated for each
rate. However, the calculation is independent of the tx rate and as such
can be precalculated and just passed in for each rate.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index 2f8af7a..26ac892 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -1861,7 +1861,8 @@
 				     int is_rate_b,
 				     enum ieee80211_band band,
 				     int power_level,
-				     u8 txpower)
+				     u8 txpower,
+				     int delta)
 {
 	u32 reg;
 	u16 eeprom;
@@ -1869,13 +1870,10 @@
 	u8 eirp_txpower;
 	u8 eirp_txpower_criterion;
 	u8 reg_limit;
-	int bw_comp;
 
 	if (!((band == IEEE80211_BAND_5GHZ) && is_rate_b))
 		return txpower;
 
-	bw_comp = rt2800_get_txpower_bw_comp(rt2x00dev, band);
-
 	if (test_bit(CONFIG_SUPPORT_POWER_LIMIT, &rt2x00dev->flags)) {
 		/*
 		 * Check if eirp txpower exceed txpower_limit.
@@ -1898,14 +1896,14 @@
 						 EEPROM_EIRP_MAX_TX_POWER_5GHZ);
 
 		eirp_txpower = eirp_txpower_criterion + (txpower - criterion) +
-				       (is_rate_b ? 4 : 0) + bw_comp;
+			       (is_rate_b ? 4 : 0) + delta;
 
 		reg_limit = (eirp_txpower > power_level) ?
 					(eirp_txpower - power_level) : 0;
 	} else
 		reg_limit = 0;
 
-	return txpower + bw_comp - reg_limit;
+	return txpower + delta - reg_limit;
 }
 
 static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev,
@@ -1919,6 +1917,12 @@
 	u32 offset;
 	enum ieee80211_band band = conf->channel->band;
 	int power_level = conf->power_level;
+	int delta;
+
+	/*
+	 * Calculate HT40 compensation delta
+	 */
+	delta = rt2800_get_txpower_bw_comp(rt2x00dev, band);
 
 	/*
 	 * set to normal bbp tx power control mode: +/- 0dBm
@@ -1948,7 +1952,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE0);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE0, txpower);
 
 		/*
@@ -1959,7 +1963,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE1);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE1, txpower);
 
 		/*
@@ -1970,7 +1974,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE2);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE2, txpower);
 
 		/*
@@ -1981,7 +1985,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE3);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE3, txpower);
 
 		/* read the next four txpower values */
@@ -1997,7 +2001,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE0);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE4, txpower);
 
 		/*
@@ -2008,7 +2012,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE1);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE5, txpower);
 
 		/*
@@ -2019,7 +2023,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE2);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE6, txpower);
 
 		/*
@@ -2030,7 +2034,7 @@
 		txpower = rt2x00_get_field16(eeprom,
 					     EEPROM_TXPOWER_BYRATE_RATE3);
 		txpower = rt2800_compesate_txpower(rt2x00dev, is_rate_b, band,
-					     power_level, txpower);
+					     power_level, txpower, delta);
 		rt2x00_set_field32(&reg, TX_PWR_CFG_RATE7, txpower);
 
 		rt2800_register_write(rt2x00dev, offset, reg);