Re: [PATCH 12/14] media: medkatek: vcodec: set secure mode to decoder driver

Hi,

On 9/11/23 17:54, Nicolas Dufresne wrote:

Hi,

Le lundi 11 septembre 2023 à 20:59 +0800, Yunfei Dong a écrit :

quoted

Setting secure mode flag to kernel when trying to play secure video,
then decoder driver will initialize tee related interface to support
svp.

This is not what the patch is doing, please rework. This patch is an vendor API
addition introducing V4L2_CID_MPEG_MTK_SET_SECURE_MODE. I should not have to
read your patch to understand this.

quoted

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
---
 .../vcodec/decoder/mtk_vcodec_dec_stateless.c     | 15 ++++++++++++++-
 drivers/media/v4l2-core/v4l2-ctrls-defs.c         |  5 +++++
 include/uapi/linux/v4l2-controls.h                |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_stateless.c b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_stateless.c
index d2b09ce9f1cf..a981178c25d9 100644
--- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_stateless.c
+++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_stateless.c

@@ -535,6 +535,17 @@ static int mtk_vdec_s_ctrl(struct v4l2_ctrl *ctrl)
 		ctrl->val = mtk_dma_contig_get_secure_handle(ctx, ctrl->val);
 		mtk_v4l2_vdec_dbg(3, ctx, "get secure handle: %d => 0x%x", sec_fd, ctrl->val);
 		break;
+	case V4L2_CID_MPEG_MTK_SET_SECURE_MODE:

Stepping back a little and focusing on the API, what makes your driver so
special that it should be the only one having a "secure mode" ? We are touching
in gap in the media pipeline in Linux, and this should come with consideration
of the global API.

Why is this API better then let's say Google Android one, were they expose 2
device nodes in their fork of the MFC driver (a secure and a non secure one) ?

Perhaps it is a good idea to first post an RFC with an uAPI proposal on how to
handle secure video. I suspect this isn't mediatek specific, other SoCs with
tee support could use this as well.

As Nicolas said, it's long known to be a gap in our media support, so it is
really great that you started work on this, but you need to look at this from
a more generic point-of-view, and not mediatek-specific.

Regards,

	Hans

regards,
Nicolas

p.s. you forgot to document your control in the RST doc, please do in following
release.

quoted

+		ctx->is_svp_mode = ctrl->val;
+
+		if (ctx->is_svp_mode) {
+			ret = mtk_vcodec_dec_optee_open(ctx->dev->optee_private);
+			if (ret)
+				mtk_v4l2_vdec_err(ctx, "open secure mode failed.");
+			else
+				mtk_v4l2_vdec_dbg(3, ctx, "decoder in secure mode: %d", ctrl->val);
+		}
+		break;
 	default:
 		mtk_v4l2_vdec_dbg(3, ctx, "Not supported to set ctrl id: 0x%x\n", hdr_ctrl->id);
 		return ret;

@@ -573,7 +584,7 @@ static int mtk_vcodec_dec_ctrls_setup(struct mtk_vcodec_dec_ctx *ctx)
 	unsigned int i;
 	struct v4l2_ctrl *ctrl;
 
-	v4l2_ctrl_handler_init(&ctx->ctrl_hdl, NUM_CTRLS + 1);
+	v4l2_ctrl_handler_init(&ctx->ctrl_hdl, NUM_CTRLS + 2);
 	if (ctx->ctrl_hdl.error) {
 		mtk_v4l2_vdec_err(ctx, "v4l2_ctrl_handler_init failed\n");
 		return ctx->ctrl_hdl.error;

@@ -592,6 +603,8 @@ static int mtk_vcodec_dec_ctrls_setup(struct mtk_vcodec_dec_ctx *ctx)
 
 	ctrl = v4l2_ctrl_new_std(&ctx->ctrl_hdl, &mtk_vcodec_dec_ctrl_ops,
 				 V4L2_CID_MPEG_MTK_GET_SECURE_HANDLE, 0, 65535, 1, 0);
+	ctrl = v4l2_ctrl_new_std(&ctx->ctrl_hdl, &mtk_vcodec_dec_ctrl_ops,
+				 V4L2_CID_MPEG_MTK_SET_SECURE_MODE, 0, 65535, 1, 0);
 
 	v4l2_ctrl_handler_setup(&ctx->ctrl_hdl);
 

diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index d8cf01f76aab..a507045a3f30 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c

@@ -1042,6 +1042,7 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_MPEG_VIDEO_REF_NUMBER_FOR_PFRAMES:	return "Reference Frames for a P-Frame";
 	case V4L2_CID_MPEG_VIDEO_PREPEND_SPSPPS_TO_IDR:		return "Prepend SPS and PPS to IDR";
 	case V4L2_CID_MPEG_MTK_GET_SECURE_HANDLE:		return "MediaTek Decoder get secure handle";
+	case V4L2_CID_MPEG_MTK_SET_SECURE_MODE:			return "MediaTek Decoder set secure mode";
 
 	/* AV1 controls */
 	case V4L2_CID_MPEG_VIDEO_AV1_PROFILE:			return "AV1 Profile";

@@ -1442,6 +1443,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 		*type = V4L2_CTRL_TYPE_INTEGER;
 		*flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
 		break;
+	case V4L2_CID_MPEG_MTK_SET_SECURE_MODE:
+		*type = V4L2_CTRL_TYPE_INTEGER;
+		*flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
+		break;
 	case V4L2_CID_USER_CLASS:
 	case V4L2_CID_CAMERA_CLASS:
 	case V4L2_CID_CODEC_CLASS:

diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 7b3694985366..88e90d943e38 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h

@@ -957,6 +957,7 @@ enum v4l2_mpeg_mfc51_video_force_frame_type {
 /*  MPEG-class control IDs specific to the MediaTek Decoder driver as defined by V4L2 */
 #define V4L2_CID_MPEG_MTK_BASE			(V4L2_CTRL_CLASS_CODEC | 0x2000)
 #define V4L2_CID_MPEG_MTK_GET_SECURE_HANDLE	(V4L2_CID_MPEG_MTK_BASE+8)
+#define V4L2_CID_MPEG_MTK_SET_SECURE_MODE	(V4L2_CID_MPEG_MTK_BASE+9)
 
 /*  Camera class control IDs */
 

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