From ff3b3b33231a6a0862f7bc605a6ddf5580316996 Mon Sep 17 00:00:00 2001
From: Jerry Chang <jerchang@nvidia.com>
Date: Tue, 9 Jan 2018 17:26:04 +0800
Subject: [PATCH] drivers: media: evaluate capture init latency

- check VI driver's capture init latency
- evaluate the latency between videobuf2 queue init
  and first captured frame release to user-space
- add debug prints for SOF and EOF

Bug 200376318
Bug 2016843

Change-Id: I7cd6c6c33c12f7bdc8b36621341b0f46eecf62f8
Signed-off-by: Jerry Chang <jerchang@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1634665
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
---
 .../media/platform/tegra/camera/vi/channel.c  | 27 +++++++++++++++++++
 .../media/platform/tegra/camera/vi/vi2_fops.c |  5 ++++
 .../media/platform/tegra/camera/vi/vi4_fops.c |  4 +++
 3 files changed, 36 insertions(+)

diff --git a/drivers/media/platform/tegra/camera/vi/channel.c b/drivers/media/platform/tegra/camera/vi/channel.c
index 115be1adec7b..46d4ff1d7458 100644
--- a/drivers/media/platform/tegra/camera/vi/channel.c
+++ b/drivers/media/platform/tegra/camera/vi/channel.c
@@ -44,6 +44,8 @@
 
 #define TPG_CSI_GROUP_ID	10
 
+static s64 queue_init_ts;
+
 static void gang_buffer_offsets(struct tegra_channel *chan)
 {
 	int i;
@@ -296,6 +298,7 @@ static void tegra_channel_fmts_bitmap_init(struct tegra_channel *chan)
 void release_buffer(struct tegra_channel *chan, struct tegra_channel_buffer* buf)
 {
 	struct vb2_v4l2_buffer* vbuf = &buf->buf;
+	s64 frame_arrived_ts = 0;
 	/* release one frame */
 	vbuf->sequence = chan->sequence++;
 	vbuf->field = V4L2_FIELD_NONE;
@@ -312,6 +315,19 @@ void release_buffer(struct tegra_channel *chan, struct tegra_channel_buffer* buf
 		buf->state = VB2_BUF_STATE_ERROR;
 	}
 
+	if (chan->sequence == 1) {
+		/*
+		 * Evaluate the initial capture latency between videobuf2 queue
+		 * and first captured frame release to user-space.
+		 */
+		frame_arrived_ts = ktime_to_ms(ktime_get());
+		dev_dbg(&chan->video.dev, "%s: capture init latency is %lld ms\n",
+			__func__, (frame_arrived_ts - queue_init_ts));
+	}
+
+	dev_dbg(&chan->video.dev,
+		"%s: release buf[%p] frame[%d] to user-space\n",
+		__func__, buf, chan->sequence);
 	vb2_buffer_done(&vbuf->vb2_buf, buf->state);
 }
 
@@ -434,6 +450,14 @@ static void tegra_channel_buffer_queue(struct vb2_buffer *vb)
 	if (chan->bypass)
 		return;
 
+	if (!queue_init_ts) {
+		/*
+		 * Record videobuf2 queue initial timestamp.
+		 * Note: latency is accurate when streaming is already turned ON
+		 */
+		queue_init_ts = ktime_to_ms(ktime_get());
+	}
+
 	/* Put buffer into the capture queue */
 	spin_lock(&chan->start_lock);
 	list_add_tail(&buf->queue, &chan->capture);
@@ -582,6 +606,9 @@ static void tegra_channel_stop_streaming(struct vb2_queue *vq)
 
 	if (vi->fops)
 		vi->fops->vi_stop_streaming(vq);
+
+	/* Clean-up recorded videobuf2 queue initial timestamp */
+	queue_init_ts = 0;
 }
 
 static const struct vb2_ops tegra_channel_queue_qops = {
diff --git a/drivers/media/platform/tegra/camera/vi/vi2_fops.c b/drivers/media/platform/tegra/camera/vi/vi2_fops.c
index f6d420e648fc..d8cb190c665c 100644
--- a/drivers/media/platform/tegra/camera/vi/vi2_fops.c
+++ b/drivers/media/platform/tegra/camera/vi/vi2_fops.c
@@ -484,6 +484,8 @@ static int tegra_channel_capture_frame(struct tegra_channel *chan,
 			chan->capture_state = CAPTURE_TIMEOUT;
 			break;
 		}
+		dev_dbg(&chan->video.dev,
+			"%s: vi2 got SOF syncpt buf[%p]\n", __func__, buf);
 	}
 
 	if (!err && !chan->pg_mode) {
@@ -617,6 +619,9 @@ static void tegra_channel_release_frame(struct tegra_channel *chan,
 		if (err)
 			dev_err(&chan->video.dev,
 				"MW_ACK_DONE syncpoint time out!%d\n", index);
+
+		dev_dbg(&chan->video.dev,
+			"%s: vi2 got EOF syncpt buf[%p]\n", __func__, buf);
 	}
 
 	if (err) {
diff --git a/drivers/media/platform/tegra/camera/vi/vi4_fops.c b/drivers/media/platform/tegra/camera/vi/vi4_fops.c
index 86c1840500e5..67763dd46b80 100644
--- a/drivers/media/platform/tegra/camera/vi/vi4_fops.c
+++ b/drivers/media/platform/tegra/camera/vi/vi4_fops.c
@@ -536,6 +536,8 @@ static int tegra_channel_capture_frame(struct tegra_channel *chan,
 
 	/* wait for vi notifier events */
 	vi_notify_wait(chan, &ts);
+	dev_dbg(&chan->video.dev,
+		"%s: vi4 got SOF syncpt buf[%p]\n", __func__, buf);
 
 	vi4_check_status(chan);
 
@@ -590,6 +592,8 @@ static void tegra_channel_release_frame(struct tegra_channel *chan,
 			dev_err(&chan->video.dev,
 				"MW_ACK_DONE syncpoint time out!%d\n", index);
 	}
+	dev_dbg(&chan->video.dev,
+		"%s: vi4 got EOF syncpt buf[%p]\n", __func__, buf);
 
 	if (err) {
 		buf->state = VB2_BUF_STATE_ERROR;
-- 
2.39.2