[PATCH 2/2] hantro: h264: Refuse to decode unsupported bitstream

[Ezequiel Garcia]

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

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

Given the JPEG compression level control is the only one
that needs setting, a specific ops is provided.

Signed-off-by: Ezequiel Garcia <ezequiel at collabora.com>
---
 drivers/staging/media/hantro/hantro_drv.c | 29 ++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
index 0db8ad455160..361ffaa821ef 100644
--- a/drivers/staging/media/hantro/hantro_drv.c
+++ b/drivers/staging/media/hantro/hantro_drv.c
@@ -261,7 +261,25 @@ queue_init(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)
 	return vb2_queue_init(dst_vq);
 }
 
-static int hantro_s_ctrl(struct v4l2_ctrl *ctrl)
+static int hantro_try_ctrl(struct v4l2_ctrl *ctrl)
+{
+	if (ctrl->id == V4L2_CID_MPEG_VIDEO_H264_SPS) {
+		const struct v4l2_ctrl_h264_sps *sps = ctrl->p_cur.p;
+
+		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 int hantro_jpeg_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct hantro_ctx *ctx;
 
@@ -282,7 +300,11 @@ static int hantro_s_ctrl(struct v4l2_ctrl *ctrl)
 }
 
 static const struct v4l2_ctrl_ops hantro_ctrl_ops = {
-	.s_ctrl = hantro_s_ctrl,
+	.try_ctrl = hantro_try_ctrl,
+};
+
+static const struct v4l2_ctrl_ops hantro_jpeg_ctrl_ops = {
+	.s_ctrl = hantro_jpeg_s_ctrl,
 };
 
 static const struct hantro_ctrl controls[] = {
@@ -294,7 +316,7 @@ static const struct hantro_ctrl controls[] = {
 			.max = 100,
 			.step = 1,
 			.def = 50,
-			.ops = &hantro_ctrl_ops,
+			.ops = &hantro_jpeg_ctrl_ops,
 		},
 	}, {
 		.codec = HANTRO_MPEG2_DECODER,
@@ -325,6 +347,7 @@ static const struct hantro_ctrl controls[] = {
 		.codec = HANTRO_H264_DECODER,
 		.cfg = {
 			.id = V4L2_CID_MPEG_VIDEO_H264_SPS,
+			.ops = &hantro_ctrl_ops,
 		},
 	}, {
 		.codec = HANTRO_H264_DECODER,
-- 
2.26.0.rc2