Bluetooth: Improve USB driver throughput by increasing the frame size

This patch increases the receive buffer size to HCI_MAX_FRAME_SIZE
which improves the RX throughput considerably.

Tested against BRM/Atheros/CSR USB Dongles with PAN profile using
iperf and chariot. This gave significant (around 40%) increase
in performance (increased from 0.8 to 1.5 Mb/s in Sheld room)

Signed-off-by: Vikram Kandukuri <vikram.kandukuri@atheros.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index e70c57ee4221..124db8cd144c 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -301,7 +301,7 @@ static int btusb_submit_bulk_urb(struct hci_dev *hdev, gfp_t mem_flags)
         struct urb *urb;
         unsigned char *buf;
         unsigned int pipe;
-        int err, size;
+        int err, size = HCI_MAX_FRAME_SIZE;
 
         BT_DBG("%s", hdev->name);
 
@@ -312,8 +312,6 @@ static int btusb_submit_bulk_urb(struct hci_dev *hdev, gfp_t mem_flags)
         if (!urb)
                 return -ENOMEM;
 
-        size = le16_to_cpu(data->bulk_rx_ep->wMaxPacketSize);
-
         buf = kmalloc(size, mem_flags);
         if (!buf) {
                 usb_free_urb(urb);