1 files changed, 37 insertions, 4 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 9e41605a276b..f064f1549333 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -191,14 +191,16 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 
 	req->started = false;
 	list_del(&req->list);
-	req->trb = NULL;
 	req->remaining = 0;
 
 	if (req->request.status == -EINPROGRESS)
 		req->request.status = status;
 
-	usb_gadget_unmap_request_by_dev(dwc->sysdev,
-					&req->request, req->direction);
+	if (req->trb)
+		usb_gadget_unmap_request_by_dev(dwc->sysdev,
+						&req->request, req->direction);
+
+	req->trb = NULL;
 
 	trace_dwc3_gadget_giveback(req);
 
@@ -894,9 +896,40 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
 		if (!node) {
 			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS_FIRST;
 
+			/*
+			 * USB Specification 2.0 Section 5.9.2 states that: "If
+			 * there is only a single transaction in the microframe,
+			 * only a DATA0 data packet PID is used.  If there are
+			 * two transactions per microframe, DATA1 is used for
+			 * the first transaction data packet and DATA0 is used
+			 * for the second transaction data packet.  If there are
+			 * three transactions per microframe, DATA2 is used for
+			 * the first transaction data packet, DATA1 is used for
+			 * the second, and DATA0 is used for the third."
+			 *
+			 * IOW, we should satisfy the following cases:
+			 *
+			 * 1) length <= maxpacket
+			 *	- DATA0
+			 *
+			 * 2) maxpacket < length <= (2 * maxpacket)
+			 *	- DATA1, DATA0
+			 *
+			 * 3) (2 * maxpacket) < length <= (3 * maxpacket)
+			 *	- DATA2, DATA1, DATA0
+			 */
 			if (speed == USB_SPEED_HIGH) {
 				struct usb_ep *ep = &dep->endpoint;
-				trb->size |= DWC3_TRB_SIZE_PCM1(ep->mult - 1);
+				unsigned int mult = ep->mult - 1;
+				unsigned int maxp = usb_endpoint_maxp(ep->desc);
+
+				if (length <= (2 * maxp))
+					mult--;
+
+				if (length <= maxp)
+					mult--;
+
+				trb->size |= DWC3_TRB_SIZE_PCM1(mult);
 			}
 		} else {
 			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;