[PATCH 2/2] usb: gadget: u_serial: improve performance for large data
From: Macpaul Lin <macpaul.lin@mediatek.com>
Date: 2020-06-16 12:35:10
Also in:
linux-mediatek, linux-usb, lkml
Subsystem:
the rest, usb subsystem · Maintainers:
Linus Torvalds, Greg Kroah-Hartman
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@mediatek.com> --- 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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel