mwifiex: improve AMSDU packet aggregation for PCIe and SDIO

For PCIe, aggregate more AMSDU packets till PCIe TXBD is full.

For SDIO, aggregation was disabled for AMSDU packets because
AMSDU aggregated packet size is already 4K or 8K, SDIO Multiport
Aggregation feature didn't use to gain much previously.
Now with increased multiport aggregation buffer, we can enable
it for AMSDU packets.
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/11n_aggr.c

@@ -236,17 +236,10 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
 		ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_USB_EP_DATA,
 						   skb_aggr, NULL);
 	} else {
-		/*
-		 * Padding per MSDU will affect the length of next
-		 * packet and hence the exact length of next packet
-		 * is uncertain here.
-		 *
-		 * Also, aggregation of transmission buffer, while
-		 * downloading the data to the card, wont gain much
-		 * on the AMSDU packets as the AMSDU packets utilizes
-		 * the transmission buffer space to the maximum
-		 * (adapter->tx_buf_size).
-		 */
+		if (skb_src)
+			tx_param.next_pkt_len =
+					skb_src->len + sizeof(struct txpd);
+		else
 			tx_param.next_pkt_len = 0;
 
 		ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,