media: cedrus: Propagate OUTPUT resolution to CAPTURE

As per spec, the CAPTURE resolution should be automatically set based on
the OUTPUT resolution. This patch properly propagate width/height to the
capture when the OUTPUT format is set and override the user provided
width/height with configured OUTPUT resolution when the CAPTURE fmt is
updated.

This also prevents userspace from selecting a CAPTURE resolution that is
too small, avoiding kernel oops.
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Tested-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/sunxi/cedrus/cedrus_video.c

@@ -247,6 +247,8 @@ static int cedrus_try_fmt_vid_cap(struct file *file, void *priv,
 		return -EINVAL;
 
 	pix_fmt->pixelformat = fmt->pixelformat;
+	pix_fmt->width = ctx->src_fmt.width;
+	pix_fmt->height = ctx->src_fmt.height;
 	cedrus_prepare_format(pix_fmt);
 
 	return 0;
@@ -296,10 +298,30 @@ static int cedrus_s_fmt_vid_out(struct file *file, void *priv,
 {
 	struct cedrus_ctx *ctx = cedrus_file2ctx(file);
 	struct vb2_queue *vq;
+	struct vb2_queue *peer_vq;
 	int ret;
 
+	ret = cedrus_try_fmt_vid_out(file, priv, f);
+	if (ret)
+		return ret;
+
 	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
-	if (vb2_is_busy(vq))
+	/*
+	 * In order to support dynamic resolution change,
+	 * the decoder admits a resolution change, as long
+	 * as the pixelformat remains. Can't be done if streaming.
+	 */
+	if (vb2_is_streaming(vq) || (vb2_is_busy(vq) &&
+	    f->fmt.pix.pixelformat != ctx->src_fmt.pixelformat))
+		return -EBUSY;
+	/*
+	 * Since format change on the OUTPUT queue will reset
+	 * the CAPTURE queue, we can't allow doing so
+	 * when the CAPTURE queue has buffers allocated.
+	 */
+	peer_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
+				  V4L2_BUF_TYPE_VIDEO_CAPTURE);
+	if (vb2_is_busy(peer_vq))
 		return -EBUSY;
 
 	ret = cedrus_try_fmt_vid_out(file, priv, f);
@@ -319,11 +341,14 @@ static int cedrus_s_fmt_vid_out(struct file *file, void *priv,
 		break;
 	}
 
-	/* Propagate colorspace information to capture. */
+	/* Propagate format information to capture. */
 	ctx->dst_fmt.colorspace = f->fmt.pix.colorspace;
 	ctx->dst_fmt.xfer_func = f->fmt.pix.xfer_func;
 	ctx->dst_fmt.ycbcr_enc = f->fmt.pix.ycbcr_enc;
 	ctx->dst_fmt.quantization = f->fmt.pix.quantization;
+	ctx->dst_fmt.width = ctx->src_fmt.width;
+	ctx->dst_fmt.height = ctx->src_fmt.height;
+	cedrus_prepare_format(&ctx->dst_fmt);
 
 	return 0;
 }