media: platform: Improve power on and power off flow

Call pm_runtime_get_sync() before starting a frame and then
pm_runtime_put() after completing it. This can save power for the time
between processing two frames.

Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Xia Jiang <xia.jiang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/mtk-jpeg/mtk_jpeg_core.c

@@ -710,23 +710,6 @@ static struct vb2_v4l2_buffer *mtk_jpeg_buf_remove(struct mtk_jpeg_ctx *ctx,
 		return v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
 }
 
-static int mtk_jpeg_start_streaming(struct vb2_queue *q, unsigned int count)
-{
-	struct mtk_jpeg_ctx *ctx = vb2_get_drv_priv(q);
-	struct vb2_v4l2_buffer *vb;
-	int ret = 0;
-
-	ret = pm_runtime_get_sync(ctx->jpeg->dev);
-	if (ret < 0)
-		goto err;
-
-	return 0;
-err:
-	while ((vb = mtk_jpeg_buf_remove(ctx, q->type)))
-		v4l2_m2m_buf_done(vb, VB2_BUF_STATE_QUEUED);
-	return ret;
-}
-
 static void mtk_jpeg_stop_streaming(struct vb2_queue *q)
 {
 	struct mtk_jpeg_ctx *ctx = vb2_get_drv_priv(q);
@@ -751,8 +734,6 @@ static void mtk_jpeg_stop_streaming(struct vb2_queue *q)
 
 	while ((vb = mtk_jpeg_buf_remove(ctx, q->type)))
 		v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
-
-	pm_runtime_put_sync(ctx->jpeg->dev);
 }
 
 static const struct vb2_ops mtk_jpeg_qops = {
@@ -761,7 +742,6 @@ static const struct vb2_ops mtk_jpeg_qops = {
 	.buf_queue          = mtk_jpeg_buf_queue,
 	.wait_prepare       = vb2_ops_wait_prepare,
 	.wait_finish        = vb2_ops_wait_finish,
-	.start_streaming    = mtk_jpeg_start_streaming,
 	.stop_streaming     = mtk_jpeg_stop_streaming,
 };
 
@@ -812,7 +792,7 @@ static void mtk_jpeg_device_run(void *priv)
 	struct mtk_jpeg_src_buf *jpeg_src_buf;
 	struct mtk_jpeg_bs bs;
 	struct mtk_jpeg_fb fb;
-	int i;
+	int i, ret;
 
 	src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
 	dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
@@ -832,6 +812,10 @@ static void mtk_jpeg_device_run(void *priv)
 		return;
 	}
 
+	ret = pm_runtime_get_sync(jpeg->dev);
+	if (ret < 0)
+		goto dec_end;
+
 	mtk_jpeg_set_dec_src(ctx, &src_buf->vb2_buf, &bs);
 	if (mtk_jpeg_set_dec_dst(ctx, &jpeg_src_buf->dec_param, &dst_buf->vb2_buf, &fb))
 		goto dec_end;
@@ -957,6 +941,7 @@ dec_end:
 	v4l2_m2m_buf_done(src_buf, buf_state);
 	v4l2_m2m_buf_done(dst_buf, buf_state);
 	v4l2_m2m_job_finish(jpeg->m2m_dev, ctx->fh.m2m_ctx);
+	pm_runtime_put(ctx->jpeg->dev);
 	return IRQ_HANDLED;
 }