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 <mian.yousaf.kaukab@stericsson.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 20 deletions

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 6d8e533..125587a 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -474,20 +474,6 @@ static int exception_in_progress(struct fsg_common *common)
 	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)
@@ -586,9 +572,9 @@ static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 	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);
 
@@ -975,7 +961,6 @@ static int do_write(struct fsg_common *common)
 			 * 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 */
@@ -1652,7 +1637,6 @@ static int throw_away_data(struct fsg_common *common)
 			 * 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 */
@@ -2322,8 +2306,8 @@ static int get_next_command(struct fsg_common *common)
 	}
 
 	/* 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;