mwifiex: fix Tx data rate display issue

"iw dev mlan0 link" shows wrong data rate, because data rate is
not sent properly to cfg80211 stack. Also stack is not updated
with mcs and Tx data flags information.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -543,12 +543,28 @@ mwifiex_dump_station_info(struct mwifiex_private *priv,
 		ret = -EFAULT;
 	}
 
+	/*
+	 * Bit 0 in tx_htinfo indicates that current Tx rate is 11n rate. Valid
+	 * MCS index values for us are 0 to 7.
+	 */
+	if ((priv->tx_htinfo & BIT(0)) && (priv->tx_rate < 8)) {
+		sinfo->txrate.mcs = priv->tx_rate;
+		sinfo->txrate.flags |= RATE_INFO_FLAGS_MCS;
+		/* 40MHz rate */
+		if (priv->tx_htinfo & BIT(1))
+			sinfo->txrate.flags |= RATE_INFO_FLAGS_40_MHZ_WIDTH;
+		/* SGI enabled */
+		if (priv->tx_htinfo & BIT(2))
+			sinfo->txrate.flags |= RATE_INFO_FLAGS_SHORT_GI;
+	}
+
 	sinfo->rx_bytes = priv->stats.rx_bytes;
 	sinfo->tx_bytes = priv->stats.tx_bytes;
 	sinfo->rx_packets = priv->stats.rx_packets;
 	sinfo->tx_packets = priv->stats.tx_packets;
 	sinfo->signal = priv->qual_level;
-	sinfo->txrate.legacy = rate.rate;
+	/* bit rate is in 500 kb/s units. Convert it to 100kb/s units */
+	sinfo->txrate.legacy = rate.rate * 5;
 
 	return ret;
 }