USB: ci13xxx_udc: fix logic to mark request dma addresses as invalid

The current driver sets the request's dma addr (mReq->req.dma) to 0 to
mark the DMA address as not valid. However some gadget drivers
(e.g. gadgetfs) set the request's dma addr to DMA_ADDR_INVALID to mark
the address as invalid. This leads to bogus data send because the
ci13xxx_udc driver assumes the request has already been mapped.

This patch fixes the problem, by using DMA_ADDR_INVALID instead of 0
to mark the request's DMA address as invalid.

Tested-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/ci13xxx_udc.c

@@ -71,6 +71,9 @@
 /******************************************************************************
  * DEFINE
  *****************************************************************************/
+
+#define DMA_ADDR_INVALID	(~(dma_addr_t)0)
+
 /* ctrl register bank access */
 static DEFINE_SPINLOCK(udc_lock);
 
@@ -1434,7 +1437,7 @@ static int _hardware_enqueue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 		return -EALREADY;
 
 	mReq->req.status = -EALREADY;
-	if (length && !mReq->req.dma) {
+	if (length && mReq->req.dma == DMA_ADDR_INVALID) {
 		mReq->req.dma = \
 			dma_map_single(mEp->device, mReq->req.buf,
 				       length, mEp->dir ? DMA_TO_DEVICE :
@@ -1453,7 +1456,7 @@ static int _hardware_enqueue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 				dma_unmap_single(mEp->device, mReq->req.dma,
 					length, mEp->dir ? DMA_TO_DEVICE :
 					DMA_FROM_DEVICE);
-				mReq->req.dma = 0;
+				mReq->req.dma = DMA_ADDR_INVALID;
 				mReq->map     = 0;
 			}
 			return -ENOMEM;
@@ -1549,7 +1552,7 @@ static int _hardware_dequeue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 	if (mReq->map) {
 		dma_unmap_single(mEp->device, mReq->req.dma, mReq->req.length,
 				 mEp->dir ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		mReq->req.dma = 0;
+		mReq->req.dma = DMA_ADDR_INVALID;
 		mReq->map     = 0;
 	}
 
@@ -2189,6 +2192,7 @@ static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
 	mReq = kzalloc(sizeof(struct ci13xxx_req), gfp_flags);
 	if (mReq != NULL) {
 		INIT_LIST_HEAD(&mReq->queue);
+		mReq->req.dma = DMA_ADDR_INVALID;
 
 		mReq->ptr = dma_pool_alloc(mEp->td_pool, gfp_flags,
 					   &mReq->dma);
@@ -2328,7 +2332,7 @@ static int ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 	if (mReq->map) {
 		dma_unmap_single(mEp->device, mReq->req.dma, mReq->req.length,
 				 mEp->dir ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		mReq->req.dma = 0;
+		mReq->req.dma = DMA_ADDR_INVALID;
 		mReq->map     = 0;
 	}
 	req->status = -ECONNRESET;