From f262ce66d40cc6858d1fcb11e7b7f960448a4f38 Mon Sep 17 00:00:00 2001
From: Michael Grzeschik <m.grzeschik@pengutronix.de>
Date: Fri, 22 Oct 2021 11:32:22 +0200
Subject: [PATCH] usb: gadget: uvc: use on returned header len in
 video_encode_isoc_sg
Git-commit: f262ce66d40cc6858d1fcb11e7b7f960448a4f38
References: git-fixes
Patch-mainline: v5.16-rc1

The function uvc_video_encode_header function returns the number of
bytes used for the header. We change the video_encode_isoc_sg function
to use the returned header_len rather than UVCG_REQUEST_HEADER_LEN and
make the encode function more flexible.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211022093223.26493-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/gadget/function/uvc_video.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 7bc865eab27b..2a9ab54bb3dc 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -104,22 +104,22 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
 	unsigned int len = video->req_size;
 	unsigned int sg_left, part = 0;
 	unsigned int i;
-	int ret;
+	int header_len;
 
 	sg = ureq->sgt.sgl;
 	sg_init_table(sg, ureq->sgt.nents);
 
 	/* Init the header. */
-	ret = uvc_video_encode_header(video, buf, ureq->header,
+	header_len = uvc_video_encode_header(video, buf, ureq->header,
 				      video->req_size);
-	sg_set_buf(sg, ureq->header, UVCG_REQUEST_HEADER_LEN);
-	len -= ret;
+	sg_set_buf(sg, ureq->header, header_len);
+	len -= header_len;
 
 	if (pending <= len)
 		len = pending;
 
 	req->length = (len == pending) ?
-		len + UVCG_REQUEST_HEADER_LEN : video->req_size;
+		len + header_len : video->req_size;
 
 	/* Init the pending sgs with payload */
 	sg = sg_next(sg);
@@ -148,7 +148,7 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
 	req->num_sgs = i + 1;
 
 	req->length -= len;
-	video->queue.buf_used += req->length - UVCG_REQUEST_HEADER_LEN;
+	video->queue.buf_used += req->length - header_len;
 
 	if (buf->bytesused == video->queue.buf_used || !buf->sg) {
 		video->queue.buf_used = 0;
-- 
2.39.0