[PATCH] media: iris: Fix VSP clock calculation for high bitrate streams

[Vishnu Reddy]

Frame drops were observed during high-resolution streams decoded at high
bitrates, as well as concurrent decode sessions. Analysis showed that the
Video Signal Processor (VSP) clock requirement was underestimated for
these workloads, resulting in insufficient clock scaling and reduced
processing throughput.

Update the VSP frequency calculation to more accurately reflect the
processing requirements of different codecs and bitrates, ensuring that
the requested clock frequency is sufficient to sustain the workload and
prevent frame drops.

Fixes: 82b96a8d8d6e ("media: iris: Move vpu35 specific api to common to use for vpu4")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
---
 drivers/media/platform/qcom/iris/iris_vpu_common.c | 29 +++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/iris/iris_vpu_common.c b/drivers/media/platform/qcom/iris/iris_vpu_common.c
index 243bd845349f..c4762229a1de 100644
--- a/drivers/media/platform/qcom/iris/iris_vpu_common.c
+++ b/drivers/media/platform/qcom/iris/iris_vpu_common.c
@@ -454,11 +454,32 @@ u64 iris_vpu2_calculate_frequency(struct iris_inst *inst, size_t data_size)
 	return max(vpp_freq, vsp_freq);
 }
 
+static u64 iris_get_vsp_ref_bitrate(struct iris_inst *inst)
+{
+	struct device *dev = inst->core->dev;
+	u32 codec = inst->codec;
+
+	switch (codec) {
+	case V4L2_PIX_FMT_H264:
+		return 150;
+	case V4L2_PIX_FMT_HEVC:
+		return 140;
+	case V4L2_PIX_FMT_VP9:
+		return 70;
+	case V4L2_PIX_FMT_AV1:
+		return 100;
+	default:
+		dev_err(dev, "Unsupported codec\n");
+		return 1;
+	}
+}
+
 u64 iris_vpu3x_vpu4x_calculate_frequency(struct iris_inst *inst, size_t data_size)
 {
 	struct platform_inst_caps *caps = inst->core->iris_platform_data->inst_caps;
 	struct v4l2_format *inp_f = inst->fmt_src;
 	u32 height, width, mbs_per_second, mbpf;
+	u64 vsp_ref_bitrate, vsp_ref_freq;
 	u64 fw_cycles, fw_vpp_cycles;
 	u64 vsp_cycles, vpp_cycles;
 	u32 fps = inst->frame_rate;
@@ -485,7 +506,13 @@ u64 iris_vpu3x_vpu4x_calculate_frequency(struct iris_inst *inst, size_t data_siz
 		vpp_cycles += div_u64(vpp_cycles * 5, 100);
 
 	vsp_cycles = fps * data_size * 8;
-	vsp_cycles = div_u64(vsp_cycles, 2);
+	vsp_ref_bitrate = iris_get_vsp_ref_bitrate(inst);
+	vsp_ref_freq = inst->codec == V4L2_PIX_FMT_AV1 ? 533 : 444;
+	vsp_cycles = div_u64(vsp_ref_freq * vsp_cycles, vsp_ref_bitrate);
+
+	/* VSP FW SW offset */
+	vsp_cycles = div_u64(vsp_cycles * 1000, 1055);
+
 	/* VSP FW overhead 1.05 */
 	vsp_cycles = div_u64(vsp_cycles * 21, 20);
 

---
base-commit: f0406245cb9855e6318335a8a223551354291a46
change-id: 20261005-fix-vsp-freq-calc-19b967b79e62

Best regards,
--  
Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>