[PATCH 2/2] media: iris: add support for vbv delay
From: Sachin Kumar Garg
Date: Thu Jul 30 2026 - 12:00:12 EST
Add the VBV_DELAY instance capability for the HFI Gen2 encoder,
exposed to userspace via V4L2_CID_MPEG_VIDEO_VBV_DELAY and mapped to
HFI_PROP_VBV_DELAY through a new iris_set_vbv_delay(). The property
is only meaningful for CBR rate-control modes.
Low VBV delay values (34-100 ms) require the encoder to run
with a single video pipe, so extend iris_set_pipe() to force
work_route to 1 whenever the configured VBV_DELAY falls in that
range.
Signed-off-by: Sachin Kumar Garg <sachin.garg@xxxxxxxxxxxxxxxx>
---
drivers/media/platform/qcom/iris/iris_ctrls.c | 31 ++++++++++++++++++++++
drivers/media/platform/qcom/iris/iris_ctrls.h | 1 +
drivers/media/platform/qcom/iris/iris_hfi_gen2.c | 12 ++++++++-
.../platform/qcom/iris/iris_hfi_gen2_defines.h | 1 +
.../platform/qcom/iris/iris_platform_common.h | 1 +
5 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/qcom/iris/iris_ctrls.c b/drivers/media/platform/qcom/iris/iris_ctrls.c
index 33114d80aa68..0ad873f3be78 100644
--- a/drivers/media/platform/qcom/iris/iris_ctrls.c
+++ b/drivers/media/platform/qcom/iris/iris_ctrls.c
@@ -154,6 +154,8 @@ static enum platform_inst_fw_cap_type iris_get_cap_id(u32 id)
return LAYER4_BITRATE_HEVC;
case V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L5_BR:
return LAYER5_BITRATE_HEVC;
+ case V4L2_CID_MPEG_VIDEO_VBV_DELAY:
+ return VBV_DELAY;
default:
return INST_FW_CAP_MAX;
}
@@ -297,6 +299,8 @@ static u32 iris_get_v4l2_id(enum platform_inst_fw_cap_type cap_id)
return V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L4_BR;
case LAYER5_BITRATE_HEVC:
return V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L5_BR;
+ case VBV_DELAY:
+ return V4L2_CID_MPEG_VIDEO_VBV_DELAY;
default:
return 0;
}
@@ -544,6 +548,11 @@ int iris_set_pipe(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id)
u32 work_route = inst->fw_caps[PIPE].value;
u32 hfi_id = inst->fw_caps[cap_id].hfi_id;
+ if (inst->domain == ENCODER) {
+ if (inst->fw_caps[VBV_DELAY].value > 34 && inst->fw_caps[VBV_DELAY].value < 100)
+ work_route = 1;
+ }
+
return hfi_ops->session_set_property(inst, hfi_id,
HFI_HOST_FLAGS_NONE,
iris_get_port_info(inst, cap_id),
@@ -1487,6 +1496,28 @@ int iris_set_layer_bitrate(struct iris_inst *inst, enum platform_inst_fw_cap_typ
&bitrate, sizeof(u32));
}
+int iris_set_vbv_delay(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id)
+{
+ const struct iris_hfi_session_ops *hfi_ops = inst->hfi_session_ops;
+ u32 hfi_id = inst->fw_caps[cap_id].hfi_id;
+ u32 rc_type = inst->hfi_rc_type;
+ u32 hfi_val;
+
+ if (rc_type != HFI_RC_CBR_VFR &&
+ rc_type != HFI_RC_CBR_CFR) {
+ dev_err(inst->core->dev, "vbv_delay unsupported, rc_type: %#x\n", rc_type);
+ return -EINVAL;
+ }
+
+ hfi_val = inst->fw_caps[cap_id].value;
+
+ return hfi_ops->session_set_property(inst, hfi_id,
+ HFI_HOST_FLAGS_NONE,
+ iris_get_port_info(inst, cap_id),
+ HFI_PAYLOAD_U32,
+ &hfi_val, sizeof(u32));
+}
+
int iris_set_properties(struct iris_inst *inst, u32 plane)
{
const struct iris_hfi_session_ops *hfi_ops = inst->hfi_session_ops;
diff --git a/drivers/media/platform/qcom/iris/iris_ctrls.h b/drivers/media/platform/qcom/iris/iris_ctrls.h
index 3c462ec9190b..16939e31c784 100644
--- a/drivers/media/platform/qcom/iris/iris_ctrls.h
+++ b/drivers/media/platform/qcom/iris/iris_ctrls.h
@@ -47,6 +47,7 @@ int iris_set_layer_type(struct iris_inst *inst, enum platform_inst_fw_cap_type c
int iris_set_layer_count_gen1(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id);
int iris_set_layer_count_gen2(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id);
int iris_set_layer_bitrate(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id);
+int iris_set_vbv_delay(struct iris_inst *inst, enum platform_inst_fw_cap_type cap_id);
int iris_set_properties(struct iris_inst *inst, u32 plane);
#endif
diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2.c b/drivers/media/platform/qcom/iris/iris_hfi_gen2.c
index 45a418fde7e9..716947f256f1 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen2.c
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2.c
@@ -944,7 +944,17 @@ static const struct platform_inst_fw_cap inst_fw_cap_sm8550_enc[] = {
.flags = CAP_FLAG_OUTPUT_PORT | CAP_FLAG_INPUT_PORT |
CAP_FLAG_DYNAMIC_ALLOWED,
.set = iris_set_layer_bitrate,
- }
+ },
+ {
+ .cap_id = VBV_DELAY,
+ .min = 34,
+ .max = 300,
+ .step_or_mask = 1,
+ .value = 300,
+ .hfi_id = HFI_PROP_VBV_DELAY,
+ .flags = CAP_FLAG_OUTPUT_PORT,
+ .set = iris_set_vbv_delay,
+ },
};
static const u32 sm8550_vdec_input_config_params_default[] = {
diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2_defines.h b/drivers/media/platform/qcom/iris/iris_hfi_gen2_defines.h
index 776b21cd11b2..19d04981cdb9 100644
--- a/drivers/media/platform/qcom/iris/iris_hfi_gen2_defines.h
+++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2_defines.h
@@ -127,6 +127,7 @@ enum hfi_flip {
#define HFI_PROP_BUFFER_MARK 0x0300016c
#define HFI_PROP_WORST_COMPRESSION_RATIO 0x03000174
#define HFI_PROP_WORST_COMPLEXITY_FACTOR 0x03000175
+#define HFI_PROP_VBV_DELAY 0x03000176
#define HFI_PROP_RAW_RESOLUTION 0x03000178
#define HFI_PROP_TOTAL_PEAK_BITRATE 0x0300017C
#define HFI_PROP_AV1_FILM_GRAIN_PRESENT 0x03000180
diff --git a/drivers/media/platform/qcom/iris/iris_platform_common.h b/drivers/media/platform/qcom/iris/iris_platform_common.h
index c9256f2323dc..a533740ced7c 100644
--- a/drivers/media/platform/qcom/iris/iris_platform_common.h
+++ b/drivers/media/platform/qcom/iris/iris_platform_common.h
@@ -183,6 +183,7 @@ enum platform_inst_fw_cap_type {
LAYER3_BITRATE_HEVC,
LAYER4_BITRATE_HEVC,
LAYER5_BITRATE_HEVC,
+ VBV_DELAY,
INST_FW_CAP_MAX,
};
--
2.34.1