usb: gadget: uvc: rework uvcg_queue_next_buffer to uvcg_complete_buffer

The function uvcg_queue_next_buffer is used different than its name
suggests. The return value nextbuf is never used by any caller. This
patch reworks the function to its actual purpose, by removing the unused
code and renaming it. The function name uvcg_complete_buffer makes it
more clear that it is actually marking the current video buffer as
complete.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220402232744.3622565-2-m.grzeschik@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/uvc_queue.c

@@ -315,24 +315,17 @@ int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
 }
 
 /* called with &queue_irqlock held.. */
-struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,
+void uvcg_complete_buffer(struct uvc_video_queue *queue,
 					  struct uvc_buffer *buf)
 {
-	struct uvc_buffer *nextbuf;
-
 	if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
 	     buf->length != buf->bytesused) {
 		buf->state = UVC_BUF_STATE_QUEUED;
 		vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
-		return buf;
+		return;
 	}
 
 	list_del(&buf->queue);
-	if (!list_empty(&queue->irqqueue))
-		nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
-					   queue);
-	else
-		nextbuf = NULL;
 
 	buf->buf.field = V4L2_FIELD_NONE;
 	buf->buf.sequence = queue->sequence++;
@@ -340,8 +333,6 @@ struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,
 
 	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
 	vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
-
-	return nextbuf;
 }
 
 struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)

drivers/usb/gadget/function/uvc_queue.h

@@ -92,7 +92,7 @@ void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect);
 
 int uvcg_queue_enable(struct uvc_video_queue *queue, int enable);
 
-struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,
+void uvcg_complete_buffer(struct uvc_video_queue *queue,
 					  struct uvc_buffer *buf);
 
 struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue);

drivers/usb/gadget/function/uvc_video.c

@@ -112,7 +112,7 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
 	if (buf->bytesused == video->queue.buf_used) {
 		video->queue.buf_used = 0;
 		buf->state = UVC_BUF_STATE_DONE;
-		uvcg_queue_next_buffer(&video->queue, buf);
+		uvcg_complete_buffer(&video->queue, buf);
 		video->fid ^= UVC_STREAM_FID;
 
 		video->payload_size = 0;
@@ -183,7 +183,7 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
 		video->queue.buf_used = 0;
 		buf->state = UVC_BUF_STATE_DONE;
 		buf->offset = 0;
-		uvcg_queue_next_buffer(&video->queue, buf);
+		uvcg_complete_buffer(&video->queue, buf);
 		video->fid ^= UVC_STREAM_FID;
 	}
 }
@@ -210,7 +210,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
 	if (buf->bytesused == video->queue.buf_used) {
 		video->queue.buf_used = 0;
 		buf->state = UVC_BUF_STATE_DONE;
-		uvcg_queue_next_buffer(&video->queue, buf);
+		uvcg_complete_buffer(&video->queue, buf);
 		video->fid ^= UVC_STREAM_FID;
 	}
 }