rkvdec: h264: Refuse to decode unsupported bitstream

The hardware only supports 4:2:2, 4:2:0 or 4:0:0 (monochrome),
8-bit or 10-bit depth content.

Verify that the SPS refers to a supported bitstream, and refuse
unsupported bitstreams by failing at TRY_EXT_CTRLS time.

The driver is currently broken on 10-bit and 4:2:2
so disallow those as well.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/rkvdec/rkvdec.c

@@ -27,6 +27,32 @@
 #include "rkvdec.h"
 #include "rkvdec-regs.h"
 
+static int rkvdec_try_ctrl(struct v4l2_ctrl *ctrl)
+{
+	if (ctrl->id == V4L2_CID_MPEG_VIDEO_H264_SPS) {
+		const struct v4l2_ctrl_h264_sps *sps = ctrl->p_new.p_h264_sps;
+		/*
+		 * TODO: The hardware supports 10-bit and 4:2:2 profiles,
+		 * but it's currently broken in the driver.
+		 * Reject them for now, until it's fixed.
+		 */
+		if (sps->chroma_format_idc > 1)
+			/* Only 4:0:0 and 4:2:0 are supported */
+			return -EINVAL;
+		if (sps->bit_depth_luma_minus8 != sps->bit_depth_chroma_minus8)
+			/* Luma and chroma bit depth mismatch */
+			return -EINVAL;
+		if (sps->bit_depth_luma_minus8 != 0)
+			/* Only 8-bit is supported */
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static const struct v4l2_ctrl_ops rkvdec_ctrl_ops = {
+	.try_ctrl = rkvdec_try_ctrl,
+};
+
 static const struct rkvdec_ctrl_desc rkvdec_h264_ctrl_descs[] = {
 	{
 		.per_request = true,
@@ -42,6 +68,7 @@ static const struct rkvdec_ctrl_desc rkvdec_h264_ctrl_descs[] = {
 		.per_request = true,
 		.mandatory = true,
 		.cfg.id = V4L2_CID_MPEG_VIDEO_H264_SPS,
+		.cfg.ops = &rkvdec_ctrl_ops,
 	},
 	{
 		.per_request = true,