From: Wu Liang feng <wulf@rock-chips.com>
Date: Mon, 6 Jun 2016 03:30:35 +0000 (+0800)
Subject: usb: dwc3: gadget: fix OUT eps buffer size alignment issue
X-Git-Tag: firefly_0821_release~2513
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bb6cd1d5aa80b373ebf183426d233d4c09692ed9;p=firefly-linux-kernel-4.4.55.git

usb: dwc3: gadget: fix OUT eps buffer size alignment issue

Per dwc3 databook "Buffer Size Rules and Zero-Length Packets",
dwc3 needs buffer size to be aligned to MaxPacketSize on ep out.

Change-Id: Iff0e9c29c02c09b93bb34fed178051c02221ecc7
Signed-off-by: Wu Liang feng <wulf@rock-chips.com>
---

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 66cc37985b0b..e735b2a88a1a 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1010,6 +1010,17 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 
 	trace_dwc3_ep_queue(req);
 
+	/*
+	 * Per databook, the total size of buffer must be a multiple
+	 * of MaxPacketSize for OUT endpoints. And MaxPacketSize is
+	 * configed for endpoints in dwc3_gadget_set_ep_config(),
+	 * set to usb_endpoint_descriptor->wMaxPacketSize.
+	 */
+	if (dep->direction == 0 &&
+	    req->request.length % dep->endpoint.desc->wMaxPacketSize)
+		req->request.length = roundup(req->request.length,
+					dep->endpoint.desc->wMaxPacketSize);
+
 	/*
 	 * We only add to our list of requests now and
 	 * start consuming the list once we get XferNotReady
@@ -1156,7 +1167,7 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
 	 * any other request.
 	 */
 	if (ret == 0 && request->zero && request->length &&
-	    (request->length % ep->maxpacket == 0))
+	    (request->length % ep->desc->wMaxPacketSize == 0))
 		ret = __dwc3_gadget_ep_queue_zlp(dwc, dep);
 
 	spin_unlock_irqrestore(&dwc->lock, flags);