mwifiex: fix 11n rx packet drop issue

Currently we check the sequence number of last packet received
against start_win. If a sequence hole is detected, start_win is
updated to next sequence number.

Since the rx sequence number is initialized to 0, a corner case
exists when BA setup happens immediately after association. As
0 is a valid sequence number, start_win gets increased to 1
incorrectly. This causes the first packet with sequence number 0
being dropped.

Initialize rx sequence number as 0xffff and skip adjusting
start_win if the sequence number remains 0xffff. The sequence
number will be updated once the first packet is received.

Cc: "3.0.y, 3.1.y, 3.2.y, 3.3.y, 3.4.y" <stable@vger.kernel.org>
Signed-off-by: Stone Piao <piaoyun@marvell.com>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Kiran Divekar <dkiran@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/11n_rxreorder.c

@@ -256,7 +256,8 @@ mwifiex_11n_create_rx_reorder_tbl(struct mwifiex_private *priv, u8 *ta,
 	else
 		last_seq = priv->rx_seq[tid];
 
-	if (last_seq >= new_node->start_win)
+	if (last_seq != MWIFIEX_DEF_11N_RX_SEQ_NUM &&
+	    last_seq >= new_node->start_win)
 		new_node->start_win = last_seq + 1;
 
 	new_node->win_size = win_size;
@@ -596,5 +597,5 @@ void mwifiex_11n_cleanup_reorder_tbl(struct mwifiex_private *priv)
 	spin_unlock_irqrestore(&priv->rx_reorder_tbl_lock, flags);
 
 	INIT_LIST_HEAD(&priv->rx_reorder_tbl_ptr);
-	memset(priv->rx_seq, 0, sizeof(priv->rx_seq));
+	mwifiex_reset_11n_rx_seq_num(priv);
 }

drivers/net/wireless/mwifiex/11n_rxreorder.h

@@ -37,6 +37,13 @@
 
 #define ADDBA_RSP_STATUS_ACCEPT 0
 
+#define MWIFIEX_DEF_11N_RX_SEQ_NUM	0xffff
+
+static inline void mwifiex_reset_11n_rx_seq_num(struct mwifiex_private *priv)
+{
+	memset(priv->rx_seq, 0xff, sizeof(priv->rx_seq));
+}
+
 int mwifiex_11n_rx_reorder_pkt(struct mwifiex_private *,
 			       u16 seqNum,
 			       u16 tid, u8 *ta,

drivers/net/wireless/mwifiex/wmm.c

@@ -404,6 +404,8 @@ mwifiex_wmm_init(struct mwifiex_adapter *adapter)
 		priv->add_ba_param.tx_win_size = MWIFIEX_AMPDU_DEF_TXWINSIZE;
 		priv->add_ba_param.rx_win_size = MWIFIEX_AMPDU_DEF_RXWINSIZE;
 
+		mwifiex_reset_11n_rx_seq_num(priv);
+
 		atomic_set(&priv->wmm.tx_pkts_queued, 0);
 		atomic_set(&priv->wmm.highest_queued_prio, HIGH_PRIO_TID);
 	}