--- zzzz-none-000/linux-3.10.107/drivers/net/wireless/rt2x00/rt2x00link.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/net/wireless/rt2x00/rt2x00link.c	2021-02-04 17:41:59.000000000 +0000
@@ -13,9 +13,7 @@
 	GNU General Public License for more details.
 
 	You should have received a copy of the GNU General Public License
-	along with this program; if not, write to the
-	Free Software Foundation, Inc.,
-	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+	along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 /*
@@ -35,50 +33,24 @@
  */
 #define DEFAULT_RSSI		-128
 
-/*
- * Helper struct and macro to work with moving/walking averages.
- * When adding a value to the average value the following calculation
- * is needed:
- *
- *        avg_rssi = ((avg_rssi * 7) + rssi) / 8;
- *
- * The advantage of this approach is that we only need 1 variable
- * to store the average in (No need for a count and a total).
- * But more importantly, normal average values will over time
- * move less and less towards newly added values this results
- * that with link tuning, the device can have a very good RSSI
- * for a few minutes but when the device is moved away from the AP
- * the average will not decrease fast enough to compensate.
- * The walking average compensates this and will move towards
- * the new values correctly allowing a effective link tuning,
- * the speed of the average moving towards other values depends
- * on the value for the number of samples. The higher the number
- * of samples, the slower the average will move.
- * We use two variables to keep track of the average value to
- * compensate for the rounding errors. This can be a significant
- * error (>5dBm) if the factor is too low.
- */
-#define AVG_SAMPLES	8
-#define AVG_FACTOR	1000
-#define MOVING_AVERAGE(__avg, __val) \
-({ \
-	struct avg_val __new; \
-	__new.avg_weight = \
-	    (__avg).avg_weight  ? \
-		((((__avg).avg_weight * ((AVG_SAMPLES) - 1)) + \
-		  ((__val) * (AVG_FACTOR))) / \
-		 (AVG_SAMPLES)) : \
-		((__val) * (AVG_FACTOR)); \
-	__new.avg = __new.avg_weight / (AVG_FACTOR); \
-	__new; \
-})
+static inline int rt2x00link_get_avg_rssi(struct ewma_rssi *ewma)
+{
+	unsigned long avg;
+
+	avg = ewma_rssi_read(ewma);
+	if (avg)
+		return -avg;
+
+	return DEFAULT_RSSI;
+}
 
 static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
 {
 	struct link_ant *ant = &rt2x00dev->link.ant;
 
-	if (ant->rssi_ant.avg && rt2x00dev->link.qual.rx_success)
-		return ant->rssi_ant.avg;
+	if (rt2x00dev->link.qual.rx_success)
+		return rt2x00link_get_avg_rssi(&ant->rssi_ant);
+
 	return DEFAULT_RSSI;
 }
 
@@ -100,8 +72,7 @@
 
 static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
 {
-	rt2x00dev->link.ant.rssi_ant.avg = 0;
-	rt2x00dev->link.ant.rssi_ant.avg_weight = 0;
+	ewma_rssi_init(&rt2x00dev->link.ant.rssi_ant);
 }
 
 static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
@@ -249,12 +220,12 @@
 	/*
 	 * Update global RSSI
 	 */
-	link->avg_rssi = MOVING_AVERAGE(link->avg_rssi, rxdesc->rssi);
+	ewma_rssi_add(&link->avg_rssi, -rxdesc->rssi);
 
 	/*
 	 * Update antenna RSSI
 	 */
-	ant->rssi_ant = MOVING_AVERAGE(ant->rssi_ant, rxdesc->rssi);
+	ewma_rssi_add(&ant->rssi_ant, -rxdesc->rssi);
 }
 
 void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
@@ -309,6 +280,7 @@
 	 */
 	rt2x00dev->link.count = 0;
 	memset(qual, 0, sizeof(*qual));
+	ewma_rssi_init(&rt2x00dev->link.avg_rssi);
 
 	/*
 	 * Restore the VGC level as stored in the registers,
@@ -363,17 +335,17 @@
 	 * collect the RSSI data we could use this. Otherwise we
 	 * must fallback to the default RSSI value.
 	 */
-	if (!link->avg_rssi.avg || !qual->rx_success)
+	if (!qual->rx_success)
 		qual->rssi = DEFAULT_RSSI;
 	else
-		qual->rssi = link->avg_rssi.avg;
+		qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);
 
 	/*
 	 * Check if link tuning is supported by the hardware, some hardware
 	 * do not support link tuning at all, while other devices can disable
 	 * the feature from the EEPROM.
 	 */
-	if (test_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags))
+	if (rt2x00_has_cap_link_tuning(rt2x00dev))
 		rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);
 
 	/*
@@ -513,7 +485,7 @@
 void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
 {
 	INIT_DELAYED_WORK(&rt2x00dev->link.agc_work, rt2x00link_agc);
-	if (test_bit(CAPABILITY_VCO_RECALIBRATION, &rt2x00dev->cap_flags))
+	if (rt2x00_has_cap_vco_recalibration(rt2x00dev))
 		INIT_DELAYED_WORK(&rt2x00dev->link.vco_work, rt2x00link_vcocal);
 	INIT_DELAYED_WORK(&rt2x00dev->link.watchdog_work, rt2x00link_watchdog);
 	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner);