[U-Boot] [PATCH v2 1/3] fastboot: OUT transaction length must be aligned to wMaxPacketSize

[Dileep Katta]

OUT transactions must be aligned to wMaxPacketSize for each transfer,
or else transfer will not complete successfully. This patch modifies
rx_bytes_expected to return a transfer length that is aligned to
wMaxPacketSize.

Note that the value of wMaxPacketSize and ep->maxpacket may not be
the same value, and it is the value of wMaxPacketSize that should be
used for alignment.

Signed-off-by: Dileep Katta <dileep.katta at linaro.org>
---
Changes from v1:
	- Corrected source of wMaxPacketSize
 drivers/usb/gadget/f_fastboot.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index a8d8205..b18452e 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -370,13 +370,20 @@ static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
 	fastboot_tx_write_str(response);
 }
 
-static unsigned int rx_bytes_expected(void)
+static unsigned int rx_bytes_expected(unsigned maxpacket)
 {
 	int rx_remain = download_size - download_bytes;
+	int rem = 0;
 	if (rx_remain < 0)
 		return 0;
 	if (rx_remain > EP_BUFFER_SIZE)
 		return EP_BUFFER_SIZE;
+	if (rx_remain < maxpacket) {
+		rx_remain = maxpacket;
+	} else if (rx_remain % maxpacket != 0) {
+		rem = rx_remain % maxpacket;
+		rx_remain = rx_remain + (maxpacket - rem);
+	}
 	return rx_remain;
 }
 
@@ -425,7 +432,7 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 
 		printf("\ndownloading of %d bytes finished\n", download_bytes);
 	} else {
-		req->length = rx_bytes_expected();
+		req->length = rx_bytes_expected(fs_ep_out.wMaxPacketSize);
 		if (req->length < ep->maxpacket)
 			req->length = ep->maxpacket;
 	}
@@ -453,7 +460,7 @@ static void cb_download(struct usb_ep *ep, struct usb_request *req)
 	} else {
 		sprintf(response, "DATA%08x", download_size);
 		req->complete = rx_handler_dl_image;
-		req->length = rx_bytes_expected();
+		req->length = rx_bytes_expected(fs_ep_out.wMaxPacketSize);
 		if (req->length < ep->maxpacket)
 			req->length = ep->maxpacket;
 	}
-- 
1.8.3.2