media: coda: do not try to propagate format if capture queue busy

The driver helpfully resets the capture queue format and selection
rectangle whenever output format is changed. This only works while
the capture queue is not busy.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/coda/coda-common.c

@@ -787,6 +787,7 @@ static int coda_s_fmt_vid_out(struct file *file, void *priv,
 {
 	struct coda_ctx *ctx = fh_to_ctx(priv);
 	struct v4l2_format f_cap;
+	struct vb2_queue *dst_vq;
 	int ret;
 
 	ret = coda_try_fmt_vid_out(file, priv, f);
@@ -802,6 +803,19 @@ static int coda_s_fmt_vid_out(struct file *file, void *priv,
 	ctx->ycbcr_enc = f->fmt.pix.ycbcr_enc;
 	ctx->quantization = f->fmt.pix.quantization;
 
+	dst_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+	if (!dst_vq)
+		return -EINVAL;
+
+	/*
+	 * Setting the capture queue format is not possible while the capture
+	 * queue is still busy. This is not an error, but the user will have to
+	 * make sure themselves that the capture format is set correctly before
+	 * starting the output queue again.
+	 */
+	if (vb2_is_busy(dst_vq))
+		return 0;
+
 	memset(&f_cap, 0, sizeof(f_cap));
 	f_cap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	coda_g_fmt(file, priv, &f_cap);