mwifiex: correct TX byte count statistics

The skb is modified in sending the TX packet. Save the original
packet length to a variable so that we can get the correct
statistics update.

Signed-off-by: Ujjal Roy <royujjal@gmail.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -222,6 +222,7 @@ mwifiex_cfg80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	tx_info = MWIFIEX_SKB_TXCB(skb);
 	tx_info->bss_num = priv->bss_num;
 	tx_info->bss_type = priv->bss_type;
+	tx_info->pkt_len = pkt_len;
 
 	mwifiex_form_mgmt_frame(skb, buf, len);
 	mwifiex_queue_tx_pkt(priv, skb);

drivers/net/wireless/mwifiex/decl.h

@@ -130,6 +130,7 @@ struct mwifiex_txinfo {
 	u8 flags;
 	u8 bss_num;
 	u8 bss_type;
+	u32 pkt_len;
 };
 
 enum mwifiex_wmm_ac_e {

drivers/net/wireless/mwifiex/main.c

@@ -648,6 +648,7 @@ mwifiex_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	tx_info = MWIFIEX_SKB_TXCB(skb);
 	tx_info->bss_num = priv->bss_num;
 	tx_info->bss_type = priv->bss_type;
+	tx_info->pkt_len = skb->len;
 
 	/* Record the current time the packet was queued; used to
 	 * determine the amount of time the packet was queued in

drivers/net/wireless/mwifiex/sta_tx.c

@@ -148,6 +148,7 @@ int mwifiex_send_null_packet(struct mwifiex_private *priv, u8 flags)
 	tx_info = MWIFIEX_SKB_TXCB(skb);
 	tx_info->bss_num = priv->bss_num;
 	tx_info->bss_type = priv->bss_type;
+	tx_info->pkt_len = data_len - (sizeof(struct txpd) + INTF_HEADER_LEN);
 	skb_reserve(skb, sizeof(struct txpd) + INTF_HEADER_LEN);
 	skb_push(skb, sizeof(struct txpd));
 

drivers/net/wireless/mwifiex/txrx.c

@@ -175,7 +175,7 @@ int mwifiex_write_data_complete(struct mwifiex_adapter *adapter,
 	mwifiex_set_trans_start(priv->netdev);
 	if (!status) {
 		priv->stats.tx_packets++;
-		priv->stats.tx_bytes += skb->len;
+		priv->stats.tx_bytes += tx_info->pkt_len;
 		if (priv->tx_timeout_cnt)
 			priv->tx_timeout_cnt = 0;
 	} else {