media: uvcvideo: Split uvc_stop_streaming()

uvc_stop_streaming() is used for meta and video nodes. Split the function
in two to avoid confusion.

Use this opportunity to rename uvc_start_streaming() to
uvc_start_streaming_video(), as it is only called by the video nodes.

Reviewed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://lore.kernel.org/r/20250616-uvc-fop-v4-3-250286570ee7@chromium.org
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

Author: ribalda

drivers/media/usb/uvc/uvc_queue.c

@@ -167,7 +167,7 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
 		uvc_video_clock_update(stream, vbuf, buf);
 }
 
-static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
+static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
@@ -186,14 +186,22 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return ret;
 }
 
-static void uvc_stop_streaming(struct vb2_queue *vq)
+static void uvc_stop_streaming_video(struct vb2_queue *vq)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
 
 	lockdep_assert_irqs_enabled();
 
-	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
-		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
+	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
+
+	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+}
+
+static void uvc_stop_streaming_meta(struct vb2_queue *vq)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+
+	lockdep_assert_irqs_enabled();
 
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
 }
@@ -203,15 +211,20 @@ static const struct vb2_ops uvc_queue_qops = {
 	.buf_prepare = uvc_buffer_prepare,
 	.buf_queue = uvc_buffer_queue,
 	.buf_finish = uvc_buffer_finish,
-	.start_streaming = uvc_start_streaming,
-	.stop_streaming = uvc_stop_streaming,
+	.start_streaming = uvc_start_streaming_video,
+	.stop_streaming = uvc_stop_streaming_video,
 };
 
 static const struct vb2_ops uvc_meta_queue_qops = {
 	.queue_setup = uvc_queue_setup,
 	.buf_prepare = uvc_buffer_prepare,
 	.buf_queue = uvc_buffer_queue,
-	.stop_streaming = uvc_stop_streaming,
+	/*
+	 * .start_streaming is not provided here. Metadata relies on video
+	 * streaming being active. If video isn't streaming, then no metadata
+	 * will arrive either.
+	 */
+	.stop_streaming = uvc_stop_streaming_meta,
 };
 
 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)