rtl8xxxu: Allocate larger RX skbs when aggregation is enabled

This adds support for allocating larger skbs for devices which
indicate they support it.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h

@@ -1247,6 +1247,7 @@ struct rtl8xxxu_priv {
 	u32 ep_tx_normal_queue:1;
 	u32 ep_tx_low_queue:1;
 	u32 has_xtalk:1;
+	u32 rx_buf_aggregation:1;
 	u8 xtalk;
 	unsigned int pipe_interrupt;
 	unsigned int pipe_in;
@@ -1330,6 +1331,7 @@ struct rtl8xxxu_fileops {
 	void (*report_connect) (struct rtl8xxxu_priv *priv,
 				u8 macid, bool connect);
 	int writeN_block_size;
+	int rx_agg_buf_size;
 	char tx_desc_size;
 	char rx_desc_size;
 	char has_s0s1;

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c

@@ -64,8 +64,6 @@ module_param_named(ht40_2g, rtl8xxxu_ht40_2g, bool, 0600);
 MODULE_PARM_DESC(ht40_2g, "Enable HT40 support on the 2.4GHz band");
 
 #define USB_VENDOR_ID_REALTEK		0x0bda
-/* Minimum IEEE80211_MAX_FRAME_LEN */
-#define RTL_RX_BUFFER_SIZE		IEEE80211_MAX_FRAME_LEN
 #define RTL8XXXU_RX_URBS		32
 #define RTL8XXXU_RX_URB_PENDING_WATER	8
 #define RTL8XXXU_TX_URBS		64
@@ -5271,12 +5269,19 @@ static void rtl8xxxu_rx_complete(struct urb *urb)
 static int rtl8xxxu_submit_rx_urb(struct rtl8xxxu_priv *priv,
 				  struct rtl8xxxu_rx_urb *rx_urb)
 {
+	struct rtl8xxxu_fileops *fops = priv->fops;
 	struct sk_buff *skb;
 	int skb_size;
 	int ret, rx_desc_sz;
 
-	rx_desc_sz = priv->fops->rx_desc_size;
-	skb_size = rx_desc_sz + RTL_RX_BUFFER_SIZE;
+	rx_desc_sz = fops->rx_desc_size;
+
+	if (priv->rx_buf_aggregation && fops->rx_agg_buf_size)
+		skb_size = fops->rx_agg_buf_size;
+	else
+		skb_size = IEEE80211_MAX_FRAME_LEN;
+	skb_size += rx_desc_sz;
+
 	skb = __netdev_alloc_skb(NULL, skb_size, GFP_KERNEL);
 	if (!skb)
 		return -ENOMEM;