linux-kernel - [RESEND PATCH v0 2/3] media: chips-media: wave5: Reduce high CPU load

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Message-Id: <20250319035034.111-3-jackson.lee@chipsnmedia.com>
Date: Wed, 19 Mar 2025 12:50:33 +0900
From: "Jackson.lee" <jackson.lee@...psnmedia.com>
To: mchehab@...nel.org,
	hverkuil-cisco@...all.nl,
	sebastian.fricke@...labora.com,
	nicolas.dufresne@...labora.com,
	bob.beckett@...labora.com,
	dafna.hirschfeld@...labora.com
Cc: linux-media@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	jackson.lee@...psnmedia.com,
	lafley.kim@...psnmedia.com,
	b-brnich@...com,
	hverkuil@...all.nl,
	nas.chung@...psnmedia.com
Subject: [RESEND PATCH v0 2/3] media: chips-media: wave5: Reduce high CPU load

From: Jackson Lee <jackson.lee@...psnmedia.com>

Since applying changes for performance improvement of decoder,
there was a problem related to high CPU load.
CPU load was more than 4 times when comparing CPU load.
The root cause was the device_run was called many times even if
there was no bitstream which should be queued.

Signed-off-by: Jackson Lee <jackson.lee@...psnmedia.com>
Signed-off-by: Nas Chung <nas.chung@...psnmedia.com>
---
 .../media/platform/chips-media/wave5/wave5-vpu-dec.c | 12 +++++++++---
 .../media/platform/chips-media/wave5/wave5-vpuapi.h  |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
index cc47da509703..5ba3aaba24ce 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
@@ -1313,10 +1313,13 @@ static void wave5_vpu_dec_buf_queue(struct vb2_buffer *vb)
 		__func__, vb->type, vb->index, vb2_plane_size(&vbuf->vb2_buf, 0),
 		vb2_plane_size(&vbuf->vb2_buf, 1), vb2_plane_size(&vbuf->vb2_buf, 2));
 
-	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
+	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
+		if (inst->empty_queue)
+			inst->empty_queue = false;
 		wave5_vpu_dec_buf_queue_src(vb);
-	else if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
+	} else if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
 		wave5_vpu_dec_buf_queue_dst(vb);
+	}
 }
 
 static int wave5_vpu_dec_allocate_ring_buffer(struct vpu_instance *inst)
@@ -1506,6 +1509,7 @@ static void wave5_vpu_dec_stop_streaming(struct vb2_queue *q)
 
 	dev_dbg(inst->dev->dev, "%s: type: %u\n", __func__, q->type);
 	pm_runtime_resume_and_get(inst->dev->dev);
+	inst->empty_queue = false;
 
 	while (check_cmd) {
 		struct queue_status_info q_status;
@@ -1622,6 +1626,7 @@ static void wave5_vpu_dec_device_run(void *priv)
 			   inst->queuing_num == 0 &&
 			   inst->state == VPU_INST_STATE_PIC_RUN) {
 			dev_dbg(inst->dev->dev, "%s: no bitstream for feeding, so skip ", __func__);
+			inst->empty_queue = true;
 			goto finish_job_and_return;
 		}
 	}
@@ -1764,7 +1769,8 @@ static int wave5_vpu_dec_job_ready(void *priv)
 				"No capture buffer ready to decode!\n");
 			break;
 		} else if (!wave5_is_draining_or_eos(inst) &&
-			   !v4l2_m2m_num_src_bufs_ready(m2m_ctx)) {
+			   (!v4l2_m2m_num_src_bufs_ready(m2m_ctx) ||
+			    inst->empty_queue)) {
 			dev_dbg(inst->dev->dev,
 				"No bitstream data to decode!\n");
 			break;
diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
index 6ca1ddc67c64..3f6e37b6be86 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
@@ -813,6 +813,7 @@ struct vpu_instance {
 	bool nv21;
 	bool eos;
 	bool retry;
+	bool empty_queue;
 	int queuing_num;
 	struct mutex feed_lock; /* lock for feeding bitstream buffers */
 	struct vpu_buf bitstream_vbuf;
-- 
2.43.0