If the hardware (like DMA engine) could support large usb request exceeds
maximum packet size, use larger buffer when performing Rx/Tx could reduce
request numbers and improve performance.
Signed-off-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
---
drivers/usb/gadget/function/u_serial.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 3cfc6e2..cdcc070 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -80,6 +80,8 @@
#define QUEUE_SIZE 16
#define WRITE_BUF_SIZE 8192 /* TX only */
#define GS_CONSOLE_BUF_SIZE 8192
+/* for hardware can do more than max packet */
+#define REQ_BUF_SIZE 4096
/* console info */
struct gs_console {
@@ -247,7 +249,8 @@ static int gs_start_tx(struct gs_port *port)
break;
req = list_entry(pool->next, struct usb_request, list);
- len = gs_send_packet(port, req->buf, in->maxpacket);
+ len = gs_send_packet(port, req->buf, in->can_exceed_maxp ?
+ REQ_BUF_SIZE : in->maxpacket);
if (len == 0) {
wake_up_interruptible(&port->drain_wait);
break;
@@ -514,7 +517,9 @@ static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head,
* be as speedy as we might otherwise be.
*/
for (i = 0; i < n; i++) {
- req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC);
+ req = gs_alloc_req(ep, ep->can_exceed_maxp ?
+ REQ_BUF_SIZE : ep->maxpacket,
+ GFP_ATOMIC);
if (!req)
return list_empty(head) ? -ENOMEM : 0;
req->complete = fn;
--
1.7.9.5
