The driver status is set to flush when flush_decoder is called.
The order of STREAMOFF ioctl for OUTPUT and CAPTURE are randomly.
If flush_decoder is called in STREAMOFF for capture queue always,
leading to get NULL dst buffer when calling STREAMOFF for output
queue before capture queue.

Need to flush decoder when stream off no matter output or capture
queue is called firstly.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
---
 .../mediatek/vcodec/decoder/mtk_vcodec_dec.c  | 47 +++++++++----------
 1 file changed, 23 insertions(+), 24 deletions(-)

diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec.c b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec.c
index d2146724f5de..2ccdffbadcda 100644
--- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec.c
+++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec.c
@@ -882,29 +882,11 @@ void vb2ops_vdec_stop_streaming(struct vb2_queue *q)
 	mtk_v4l2_vdec_dbg(3, ctx, "[%d] (%d) state=(%x) ctx->decoded_frame_cnt=%d",
 			  ctx->id, q->type, ctx->state, ctx->decoded_frame_cnt);
 
-	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
-		while ((src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx))) {
-			if (src_buf != &ctx->empty_flush_buf.vb) {
-				struct media_request *req =
-					src_buf->vb2_buf.req_obj.req;
-
-				v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
-				if (req) {
-					v4l2_ctrl_request_complete(req, &ctx->ctrl_hdl);
-					media_request_manual_complete(req);
-				}
-			}
-		}
-		return;
-	}
-
-	if (ctx->state >= MTK_STATE_HEADER) {
-
-		/* Until STREAMOFF is called on the CAPTURE queue
-		 * (acknowledging the event), the driver operates
-		 * as if the resolution hasn't changed yet, i.e.
-		 * VIDIOC_G_FMT< etc. return previous resolution.
-		 * So we update picinfo here
+	if (ctx->state >= MTK_STATE_HEADER && ctx->state != MTK_STATE_FLUSH) {
+		/*
+		 * The resolution hasn't been changed when STREAMOFF is called.
+		 * Update the picinfo here with previous resolution if VIDIOC_G_FMT
+		 * is called.
 		 */
 		ctx->picinfo = ctx->last_decoded_picinfo;
 
@@ -919,8 +901,25 @@ void vb2ops_vdec_stop_streaming(struct vb2_queue *q)
 		ret = ctx->dev->vdec_pdata->flush_decoder(ctx);
 		if (ret)
 			mtk_v4l2_vdec_err(ctx, "DecodeFinal failed, ret=%d", ret);
+
+		ctx->state = MTK_STATE_FLUSH;
+	}
+
+	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
+		while ((src_buf = v4l2_m2m_src_buf_remove(ctx->m2m_ctx))) {
+			if (src_buf != &ctx->empty_flush_buf.vb) {
+				struct media_request *req =
+					src_buf->vb2_buf.req_obj.req;
+
+				v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
+				if (req) {
+					v4l2_ctrl_request_complete(req, &ctx->ctrl_hdl);
+					media_request_manual_complete(req);
+				}
+			}
+		}
+		return;
 	}
-	ctx->state = MTK_STATE_FLUSH;
 
 	while ((dst_buf = v4l2_m2m_dst_buf_remove(ctx->m2m_ctx))) {
 		vb2_set_plane_payload(&dst_buf->vb2_buf, 0, 0);
-- 
2.46.0