usb: usb_storage: do not align length of request for CBW to maxp size

Mass-storage and file-storage gadgets align the length to maximum-packet-size
when preparing the request to receive CBW. This is unnecessary and prevents the
controller driver from knowing that a short-packet is expected.

It is incorrect to set short_not_ok when preparing the request to receive CBW.
CBW will be a short-packet so short_not_ok must not be set.

This makes bh->bulk_out_intended_length unnecessary so it is also removed.

Signed-off-by: Mian Yousaf Kaukab <[e-mail]>
Acked-by: Michal Nazarewicz <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/f_mass_storage.c

···
 	return common->state > FSG_STATE_IDLE;
 }
 
-/* Make bulk-out requests be divisible by the maxpacket size */
-static void set_bulk_out_req_length(struct fsg_common *common,
-				    struct fsg_buffhd *bh, unsigned int length)
-{
-	unsigned int	rem;
-
-	bh->bulk_out_intended_length = length;
-	rem = length % common->bulk_out_maxpacket;
-	if (rem > 0)
-		length += common->bulk_out_maxpacket - rem;
-	bh->outreq->length = length;
-}
-
-
 /*-------------------------------------------------------------------------*/
 
 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
···
 	struct fsg_buffhd	*bh = req->context;
 
 	dump_msg(common, "bulk-out", req->buf, req->actual);
-	if (req->status || req->actual != bh->bulk_out_intended_length)
+	if (req->status || req->actual != req->length)
 		DBG(common, "%s --> %d, %u/%u\n", __func__,
-		    req->status, req->actual, bh->bulk_out_intended_length);
+		    req->status, req->actual, req->length);
 	if (req->status == -ECONNRESET)		/* Request was cancelled */
 		usb_ep_fifo_flush(ep);
 
···
 			 * the bulk-out maxpacket size
 			 */
 			bh->outreq->length = amount;
-			bh->bulk_out_intended_length = amount;
 			bh->outreq->short_not_ok = 1;
 			if (!start_out_transfer(common, bh))
 				/* Dunno what to do if common->fsg is NULL */
···
 			 * the bulk-out maxpacket size.
 			 */
 			bh->outreq->length = amount;
-			bh->bulk_out_intended_length = amount;
 			bh->outreq->short_not_ok = 1;
 			if (!start_out_transfer(common, bh))
 				/* Dunno what to do if common->fsg is NULL */
···
 	}
 
 	/* Queue a request to read a Bulk-only CBW */
-	set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
-	bh->outreq->short_not_ok = 1;
+	bh->outreq->length = USB_BULK_CB_WRAP_LEN;
+	bh->outreq->short_not_ok = 0;
 	if (!start_out_transfer(common, bh))
 		/* Don't know what to do if common->fsg is NULL */
 		return -EIO;

drivers/usb/gadget/file_storage.c

···
 	return (fsg->state > FSG_STATE_IDLE);
 }
 
-/* Make bulk-out requests be divisible by the maxpacket size */
-static void set_bulk_out_req_length(struct fsg_dev *fsg,
-		struct fsg_buffhd *bh, unsigned int length)
-{
-	unsigned int	rem;
-
-	bh->bulk_out_intended_length = length;
-	rem = length % fsg->bulk_out_maxpacket;
-	if (rem > 0)
-		length += fsg->bulk_out_maxpacket - rem;
-	bh->outreq->length = length;
-}
-
 static struct fsg_dev			*the_fsg;
 static struct usb_gadget_driver		fsg_driver;
 
···
 	struct fsg_buffhd	*bh = req->context;
 
 	dump_msg(fsg, "bulk-out", req->buf, req->actual);
-	if (req->status || req->actual != bh->bulk_out_intended_length)
+	if (req->status || req->actual != req->length)
 		DBG(fsg, "%s --> %d, %u/%u\n", __func__,
-				req->status, req->actual,
-				bh->bulk_out_intended_length);
+				req->status, req->actual, req->length);
 	if (req->status == -ECONNRESET)		// Request was cancelled
 		usb_ep_fifo_flush(ep);
 
···
 
 			/* amount is always divisible by 512, hence by
 			 * the bulk-out maxpacket size */
-			bh->outreq->length = bh->bulk_out_intended_length =
-					amount;
+			bh->outreq->length = amount;
 			bh->outreq->short_not_ok = 1;
 			start_transfer(fsg, fsg->bulk_out, bh->outreq,
 					&bh->outreq_busy, &bh->state);
···
 
 			/* amount is always divisible by 512, hence by
 			 * the bulk-out maxpacket size */
-			bh->outreq->length = bh->bulk_out_intended_length =
-					amount;
+			bh->outreq->length = amount;
 			bh->outreq->short_not_ok = 1;
 			start_transfer(fsg, fsg->bulk_out, bh->outreq,
 					&bh->outreq_busy, &bh->state);
···
 		}
 
 		/* Queue a request to read a Bulk-only CBW */
-		set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
-		bh->outreq->short_not_ok = 1;
+		bh->outreq->length = USB_BULK_CB_WRAP_LEN;
+		bh->outreq->short_not_ok = 0;
 		start_transfer(fsg, fsg->bulk_out, bh->outreq,
 				&bh->outreq_busy, &bh->state);
 

drivers/usb/gadget/storage_common.c

···
 	enum fsg_buffer_state		state;
 	struct fsg_buffhd		*next;
 
-	/*
-	 * The NetChip 2280 is faster, and handles some protocol faults
-	 * better, if we don't submit any short bulk-out read requests.
-	 * So we will record the intended request length here.
-	 */
-	unsigned int			bulk_out_intended_length;
-
 	struct usb_request		*inreq;
 	int				inreq_busy;
 	struct usb_request		*outreq;