-----Original Message----- From: Marcel Holtmann [mailto:marcel@xxxxxxxxxxxx] Sent: Friday, June 19, 2009 1:51 PM To: Vikram Kandukuri Cc: linux-bluetooth@xxxxxxxxxxxxxxx Subject: Re: [PATCH] Bluetooth: Improve the throughput by increasing the frame size. Hi Vikram, > This patch increases the receive buffer size to HCI_MAX_FRAME_SIZE > which improves the Rx throughput considerably. > > Signed-off-by: Vikram Kandukuri <Vikram.Kandukuri@xxxxxxxxxxx> > --- > drivers/bluetooth/btusb.c | 4 +--- > 1 files changed, 1 insertions(+), 3 deletions(-) > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c > index e70c57e..124db8c 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); > - and we can ignore the wMaxPacketSize because. It would be nice to get a reason here and that this has been tested at least with a handful of devices. Regards Marcel Hi Marcel, When we are testing PAN profile with throughput run, we observed low rx throughput. We have referred hci_usb.c and found they have used HCI_MAX_FRAME_SIZE. This increases the bulk endpoint size to 1028 bytes. This change gave significant (around 40%) increase in performance (increase from .8 to 1.5 Mb/s in shield room) We have tested with BRM/Atheros/CSR USB dongles with PAN profile. We have tested with iperf and Chariot scripts. Let me know if you need more information. Thanks, Vikram -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
