usb: gadget: fastboot: improve download progress bar

When download is ongoing, if the actual size of one transfer
is not the same as BYTES_PER_DOT, which will cause the dot
won't print anymore. Then it will let the user thinking it
is stuck, actually it is transfering without dot printed.

So, improve the method to show the progress bar (print dot).

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Marek Vasut <marex@denx.de>

drivers/usb/gadget/f_fastboot.c

@@ -386,6 +386,7 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 	unsigned int transfer_size = download_size - download_bytes;
 	const unsigned char *buffer = req->buf;
 	unsigned int buffer_size = req->actual;
+	unsigned int pre_dot_num, now_dot_num;
 
 	if (req->status != 0) {
 		printf("Bad status: %d\n", req->status);
@@ -398,7 +399,15 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 	memcpy((void *)CONFIG_USB_FASTBOOT_BUF_ADDR + download_bytes,
 	       buffer, transfer_size);
 
+	pre_dot_num = download_bytes / BYTES_PER_DOT;
 	download_bytes += transfer_size;
+	now_dot_num = download_bytes / BYTES_PER_DOT;
+
+	if (pre_dot_num != now_dot_num) {
+		putc('.');
+		if (!(now_dot_num % 74))
+			putc('\n');
+	}
 
 	/* Check if transfer is done */
 	if (download_bytes >= download_size) {
@@ -420,11 +429,6 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 			req->length = ep->maxpacket;
 	}
 
-	if (download_bytes && !(download_bytes % BYTES_PER_DOT)) {
-		putc('.');
-		if (!(download_bytes % (74 * BYTES_PER_DOT)))
-			putc('\n');
-	}
 	req->actual = 0;
 	usb_ep_queue(ep, req, 0);
 }