From 1ebf02787a1621143ecde48db86459067f9544e5 Mon Sep 17 00:00:00 2001
From: Troy Kisky <troy.kisky@boundarydevices.com>
Date: Thu, 10 Oct 2013 15:28:01 -0700
Subject: [PATCH] usb: gadget: mv_udc: optimize bounce

Only perform one copy, either in the bounce
routine for IN transfers, or the debounce
rtn for OUT transfer.

On out transfers, only copy the number
of bytes received from the bounce buffer

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
---
 drivers/usb/gadget/mv_udc.c | 37 ++++++++++++++++---------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/usb/gadget/mv_udc.c b/drivers/usb/gadget/mv_udc.c
index 24c3e4f118..1c5760535e 100644
--- a/drivers/usb/gadget/mv_udc.c
+++ b/drivers/usb/gadget/mv_udc.c
@@ -261,7 +261,7 @@ static int mv_ep_disable(struct usb_ep *ep)
 	return 0;
 }
 
-static int mv_bounce(struct mv_ep *ep)
+static int mv_bounce(struct mv_ep *ep, int in)
 {
 	uint32_t addr = (uint32_t)ep->req.buf;
 	uint32_t ba;
@@ -290,8 +290,8 @@ align:
 		if (!ep->b_buf)
 			return -ENOMEM;
 	}
-
-	memcpy(ep->b_buf, ep->req.buf, ep->req.length);
+	if (in)
+		memcpy(ep->b_buf, ep->req.buf, ep->req.length);
 
 flush:
 	ba = (uint32_t)ep->b_buf;
@@ -300,29 +300,25 @@ flush:
 	return 0;
 }
 
-static void mv_debounce(struct mv_ep *ep)
+static void mv_debounce(struct mv_ep *ep, int in)
 {
 	uint32_t addr = (uint32_t)ep->req.buf;
 	uint32_t ba = (uint32_t)ep->b_buf;
 
+	if (in) {
+		if (addr == ba)
+			return;		/* not a bounce */
+		goto free;
+	}
 	invalidate_dcache_range(ba, ba + ep->b_len);
 
-	/* Input buffer address is not aligned. */
-	if (addr & (ARCH_DMA_MINALIGN - 1))
-		goto copy;
+	if (addr == ba)
+		return;		/* not a bounce */
 
-	/* Input buffer length is not aligned. */
-	if (ep->req.length & (ARCH_DMA_MINALIGN - 1))
-		goto copy;
-
-	/* The buffer is well aligned, only invalidate cache. */
-	return;
-
-copy:
 	memcpy(ep->req.buf, ep->b_buf, ep->req.length);
-
+free:
 	/* Large payloads use allocated buffer, free it. */
-	if (ep->req.length > 64)
+	if (ep->b_buf != ep->b_fast)
 		free(ep->b_buf);
 }
 
@@ -340,7 +336,7 @@ static int mv_ep_queue(struct usb_ep *ep,
 	head = mv_get_qh(num, in);
 	len = req->length;
 
-	ret = mv_bounce(mv_ep);
+	ret = mv_bounce(mv_ep, in);
 	if (ret)
 		return ret;
 
@@ -383,10 +379,9 @@ static void handle_ep_complete(struct mv_ep *ep)
 		       num, in ? "in" : "out", item->info, item->page0);
 
 	len = (item->info >> 16) & 0x7fff;
-
-	mv_debounce(ep);
-
 	ep->req.length -= len;
+	mv_debounce(ep, in);
+
 	DBG("ept%d %s complete %x\n",
 			num, in ? "in" : "out", len);
 	ep->req.complete(&ep->ep, &ep->req);