[PATCH v4] media: iris: add FPS calculation and VPP FW overhead in frequency formula

[PATCH v4] media: iris: add FPS calculation and VPP FW overhead in frequency formula

[Vishnu Reddy]

The driver was using a fixed default FPS value when calculating the VPU
frequency. This caused wrong frequency requests for high‑frame‑rate
streams, for example 4K at 240 FPS. Because of this, the hardware was
running at a lower frequency than needed.

Add the FPS measurement based on the decoder input buffer arrival rate.
The measured FPS is stored per instance and used in frequency calculation
instead of the fixed default FPS. The value is clamped so that it does
not exceed platform limits. Add a VPP firmware overhead when running in
STAGE_2.

Signed-off-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
---
Changes in v4:
- Renamed the variable names (Vikash Garodia)
- Updated the fps calculation logic (Vikash Garodia)
- Link to v3: https://lore.kernel.org/r/20260325-update_fps_calculation-v3-1-b2ec654f7e4d@oss.qualcomm.com

Changes in v3:
- Updated the frame_count condition check (Vikash Garodia)
- Link to v2: https://lore.kernel.org/r/20260305-update_fps_calculation-v2-1-e3b5cccb1246@oss.qualcomm.com

Changes in v2:
- Replaced div_u64 with mult_frac (Konrad Dybcio)
- Link to v1: https://lore.kernel.org/r/20260304-update_fps_calculation-v1-1-4eeac373a504@oss.qualcomm.com
---
 drivers/media/platform/qcom/iris/iris_instance.h   |  2 ++
 drivers/media/platform/qcom/iris/iris_vdec.c       | 20 ++++++++++++++++++++
 drivers/media/platform/qcom/iris/iris_vpu_common.c |  6 +++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/iris/iris_instance.h b/drivers/media/platform/qcom/iris/iris_instance.h
index 16965150f427..a47cd949645f 100644
--- a/drivers/media/platform/qcom/iris/iris_instance.h
+++ b/drivers/media/platform/qcom/iris/iris_instance.h
@@ -109,6 +109,8 @@ struct iris_inst {
 	u32				metadata_idx;
 	u32				codec;
 	bool				last_buffer_dequeued;
+	u64				last_buf_ns;
+	u32				frame_counter;
 	u32				frame_rate;
 	u32				operating_rate;
 	u32				hfi_rc_type;
diff --git a/drivers/media/platform/qcom/iris/iris_vdec.c b/drivers/media/platform/qcom/iris/iris_vdec.c
index 719217399a30..7fb45df37db6 100644
--- a/drivers/media/platform/qcom/iris/iris_vdec.c
+++ b/drivers/media/platform/qcom/iris/iris_vdec.c
@@ -54,6 +54,7 @@ int iris_vdec_inst_init(struct iris_inst *inst)
 	f->fmt.pix_mp.quantization = V4L2_QUANTIZATION_DEFAULT;
 	inst->buffers[BUF_OUTPUT].min_count = iris_vpu_buf_count(inst, BUF_OUTPUT);
 	inst->buffers[BUF_OUTPUT].size = f->fmt.pix_mp.plane_fmt[0].sizeimage;
+	inst->frame_rate = MAXIMUM_FPS;
 
 	memcpy(&inst->fw_caps[0], &core->inst_fw_caps_dec[0],
 	       INST_FW_CAP_MAX * sizeof(struct platform_inst_fw_cap));
@@ -369,6 +370,8 @@ int iris_vdec_streamon_input(struct iris_inst *inst)
 	if (ret)
 		return ret;
 
+	inst->frame_counter = 0;
+
 	return iris_process_streamon_input(inst);
 }
 
@@ -411,6 +414,7 @@ int iris_vdec_qbuf(struct iris_inst *inst, struct vb2_v4l2_buffer *vbuf)
 {
 	struct iris_buffer *buf = to_iris_buffer(vbuf);
 	struct vb2_buffer *vb2 = &vbuf->vb2_buf;
+	u64 cur_buf_ns, delta_ns;
 	struct vb2_queue *q;
 	int ret;
 
@@ -427,6 +431,22 @@ int iris_vdec_qbuf(struct iris_inst *inst, struct vb2_v4l2_buffer *vbuf)
 		return 0;
 	}
 
+	if (buf->type == BUF_INPUT) {
+		cur_buf_ns = ktime_get_ns();
+
+		if (!inst->frame_counter)
+			inst->last_buf_ns = cur_buf_ns;
+
+		inst->frame_counter++;
+		delta_ns = cur_buf_ns - inst->last_buf_ns;
+
+		if (delta_ns >= NSEC_PER_SEC) {
+			inst->frame_rate = clamp_t(u32, inst->frame_counter, DEFAULT_FPS,
+						   MAXIMUM_FPS);
+			inst->frame_counter = 0;
+		}
+	}
+
 	iris_scale_power(inst);
 
 	return iris_queue_buffer(inst, buf);
diff --git a/drivers/media/platform/qcom/iris/iris_vpu_common.c b/drivers/media/platform/qcom/iris/iris_vpu_common.c
index 548e5f1727fd..d621ccffa868 100644
--- a/drivers/media/platform/qcom/iris/iris_vpu_common.c
+++ b/drivers/media/platform/qcom/iris/iris_vpu_common.c
@@ -416,7 +416,7 @@ u64 iris_vpu3x_vpu4x_calculate_frequency(struct iris_inst *inst, size_t data_siz
 	u32 height, width, mbs_per_second, mbpf;
 	u64 fw_cycles, fw_vpp_cycles;
 	u64 vsp_cycles, vpp_cycles;
-	u32 fps = DEFAULT_FPS;
+	u32 fps = inst->frame_rate;
 
 	width = max(inp_f->fmt.pix_mp.width, inst->crop.width);
 	height = max(inp_f->fmt.pix_mp.height, inst->crop.height);
@@ -435,6 +435,10 @@ u64 iris_vpu3x_vpu4x_calculate_frequency(struct iris_inst *inst, size_t data_siz
 	if (inst->fw_caps[PIPE].value > 1)
 		vpp_cycles += div_u64(vpp_cycles * 59, 1000);
 
+	/* 1.05 is VPP FW overhead */
+	if (inst->fw_caps[STAGE].value == STAGE_2)
+		vpp_cycles += mult_frac(vpp_cycles, 5, 100);
+
 	vsp_cycles = fps * data_size * 8;
 	vsp_cycles = div_u64(vsp_cycles, 2);
 	/* VSP FW overhead 1.05 */

---
base-commit: f505e978d1a0442adbbde48aed38c084ddea6d6e
change-id: 20260304-update_fps_calculation-98ee7f7507b1

Best regards,
-- 
Vishnu Reddy <busanna.reddy@oss.qualcomm.com>

Re: [PATCH v4] media: iris: add FPS calculation and VPP FW overhead in frequency formula

[Vikash Garodia]

On 3/25/2026 10:05 PM, Vishnu Reddy wrote:
> The driver was using a fixed default FPS value when calculating the VPU
> frequency. This caused wrong frequency requests for high‑frame‑rate
> streams, for example 4K at 240 FPS. Because of this, the hardware was
> running at a lower frequency than needed.
> 
> Add the FPS measurement based on the decoder input buffer arrival rate.
> The measured FPS is stored per instance and used in frequency calculation
> instead of the fixed default FPS. The value is clamped so that it does
> not exceed platform limits. Add a VPP firmware overhead when running in
> STAGE_2.
> 
> Signed-off-by: Vishnu Reddy<busanna.reddy@oss.qualcomm.com>
> ---

Reviewed-by: Vikash Garodia <vikash.garodia@oss.qualcomm.com>