diff --git a/driver/vidc/inc/msm_vidc_driver.h b/driver/vidc/inc/msm_vidc_driver.h
index 9458225c8b..90fb2c3dac 100644
--- a/driver/vidc/inc/msm_vidc_driver.h
+++ b/driver/vidc/inc/msm_vidc_driver.h
@@ -492,10 +492,6 @@ bool msm_vidc_allow_metadata_subscription(struct msm_vidc_inst *inst,
 bool msm_vidc_allow_property(struct msm_vidc_inst *inst, u32 hfi_id);
 int msm_vidc_update_property_cap(struct msm_vidc_inst *inst, u32 hfi_id,
 	bool allow);
-bool msm_vidc_allow_reqbufs(struct msm_vidc_inst *inst, u32 type);
-enum msm_vidc_allow msm_vidc_allow_stop(struct msm_vidc_inst *inst);
-bool msm_vidc_allow_start(struct msm_vidc_inst *inst);
-bool msm_vidc_allow_streamon(struct msm_vidc_inst *inst, u32 type);
 enum msm_vidc_allow msm_vidc_allow_input_psc(struct msm_vidc_inst *inst);
 bool msm_vidc_allow_drain_last_flag(struct msm_vidc_inst *inst);
 bool msm_vidc_allow_psc_last_flag(struct msm_vidc_inst *inst);
diff --git a/driver/vidc/inc/msm_vidc_state.h b/driver/vidc/inc/msm_vidc_state.h
index d995a044da..6dec161d3a 100644
--- a/driver/vidc/inc/msm_vidc_state.h
+++ b/driver/vidc/inc/msm_vidc_state.h
@@ -91,6 +91,8 @@ const char *core_state_name(enum msm_vidc_core_state state);
 const char *core_sub_state_name(enum msm_vidc_core_sub_state sub_state);
 
 /* inst statemachine functions */
+bool is_drc_pending(struct msm_vidc_inst *inst);
+bool is_drain_pending(struct msm_vidc_inst *inst);
 int msm_vidc_update_state(struct msm_vidc_inst *inst,
 	enum msm_vidc_state request_state, const char *func);
 int msm_vidc_change_state(struct msm_vidc_inst *inst,
diff --git a/driver/vidc/src/msm_vdec.c b/driver/vidc/src/msm_vdec.c
index 50396430c1..6e8cf27907 100644
--- a/driver/vidc/src/msm_vdec.c
+++ b/driver/vidc/src/msm_vdec.c
@@ -2091,17 +2091,9 @@ static int msm_vdec_alloc_and_queue_additional_dpb_buffers(struct msm_vidc_inst
 
 int msm_vdec_stop_cmd(struct msm_vidc_inst *inst)
 {
-	enum msm_vidc_allow allow = MSM_VIDC_DISALLOW;
 	int rc = 0;
 
 	i_vpr_h(inst, "received cmd: drain\n");
-	allow = msm_vidc_allow_stop(inst);
-	if (allow == MSM_VIDC_DISALLOW)
-		return -EBUSY;
-	else if (allow == MSM_VIDC_IGNORE)
-		return 0;
-	else if (allow != MSM_VIDC_ALLOW)
-		return -EINVAL;
 	rc = msm_vidc_process_drain(inst);
 	if (rc)
 		return rc;
@@ -2132,9 +2124,6 @@ int msm_vdec_start_cmd(struct msm_vidc_inst *inst)
 		return -EINVAL;
 	}
 
-	if (!msm_vidc_allow_start(inst))
-		return -EBUSY;
-
 	/* tune power features */
 	inst->decode_batch.enable = msm_vidc_allow_decode_batch(inst);
 	msm_vidc_allow_dcvs(inst);
diff --git a/driver/vidc/src/msm_venc.c b/driver/vidc/src/msm_venc.c
index 82e9196d50..71a9f6db42 100644
--- a/driver/vidc/src/msm_venc.c
+++ b/driver/vidc/src/msm_venc.c
@@ -921,17 +921,9 @@ int msm_venc_qbuf(struct msm_vidc_inst *inst, struct vb2_buffer *vb2)
 
 int msm_venc_stop_cmd(struct msm_vidc_inst *inst)
 {
-	enum msm_vidc_allow allow = MSM_VIDC_DISALLOW;
 	int rc = 0;
 
 	i_vpr_h(inst, "received cmd: drain\n");
-	allow = msm_vidc_allow_stop(inst);
-	if (allow == MSM_VIDC_DISALLOW)
-		return -EBUSY;
-	else if (allow == MSM_VIDC_IGNORE)
-		return 0;
-	else if (allow != MSM_VIDC_ALLOW)
-		return -EINVAL;
 	rc = msm_vidc_process_drain(inst);
 	if (rc)
 		return rc;
@@ -944,8 +936,7 @@ int msm_venc_start_cmd(struct msm_vidc_inst *inst)
 	int rc = 0;
 
 	i_vpr_h(inst, "received cmd: resume\n");
-	if (!msm_vidc_allow_start(inst))
-		return -EBUSY;
+
 	vb2_clear_last_buffer_dequeued(inst->bufq[OUTPUT_META_PORT].vb2q);
 	vb2_clear_last_buffer_dequeued(inst->bufq[OUTPUT_PORT].vb2q);
 
diff --git a/driver/vidc/src/msm_vidc.c b/driver/vidc/src/msm_vidc.c
index 449ffee961..4c3b21469c 100644
--- a/driver/vidc/src/msm_vidc.c
+++ b/driver/vidc/src/msm_vidc.c
@@ -253,9 +253,6 @@ int msm_vidc_s_fmt(void *instance, struct v4l2_format *f)
 		return -EINVAL;
 	}
 
-	if (!msm_vidc_allow_s_fmt(inst, f->type))
-		return -EBUSY;
-
 	if (inst->domain == MSM_VIDC_DECODER)
 		rc = msm_vdec_s_fmt(inst, f);
 	if (inst->domain == MSM_VIDC_ENCODER)
@@ -400,11 +397,6 @@ int msm_vidc_reqbufs(void *instance, struct v4l2_requestbuffers *b)
 		return -EINVAL;
 	}
 
-	if (!msm_vidc_allow_reqbufs(inst, b->type)) {
-		rc = -EBUSY;
-		goto exit;
-	}
-
 	port = v4l2_type_to_driver_port(inst, b->type, __func__);
 	if (port < 0) {
 		rc = -EINVAL;
diff --git a/driver/vidc/src/msm_vidc_driver.c b/driver/vidc/src/msm_vidc_driver.c
index a2745b1fb8..0aa3afbd52 100644
--- a/driver/vidc/src/msm_vidc_driver.c
+++ b/driver/vidc/src/msm_vidc_driver.c
@@ -1115,111 +1115,6 @@ int msm_vidc_update_property_cap(struct msm_vidc_inst *inst, u32 hfi_id,
 	return rc;
 }
 
-bool msm_vidc_allow_reqbufs(struct msm_vidc_inst *inst, u32 type)
-{
-	bool allow = false;
-
-	if (!inst) {
-		d_vpr_e("%s: invalid params\n", __func__);
-		return false;
-	}
-	if (is_state(inst, MSM_VIDC_OPEN)) {
-		allow = true;
-		goto exit;
-	}
-	if (type == OUTPUT_MPLANE || type == OUTPUT_META_PLANE) {
-		if (is_state(inst, MSM_VIDC_INPUT_STREAMING)) {
-			allow = true;
-			goto exit;
-		}
-	}
-	if (type == INPUT_MPLANE || type == INPUT_META_PLANE) {
-		if (is_state(inst, MSM_VIDC_OUTPUT_STREAMING)) {
-			allow = true;
-			goto exit;
-		}
-	}
-
-exit:
-	if (!allow)
-		i_vpr_e(inst, "%s: type %d not allowed in state %s\n",
-				__func__, type, state_name(inst->state));
-	return allow;
-}
-
-enum msm_vidc_allow msm_vidc_allow_stop(struct msm_vidc_inst *inst)
-{
-	enum msm_vidc_allow allow = MSM_VIDC_DISALLOW;
-
-	if (!inst) {
-		d_vpr_e("%s: invalid params\n", __func__);
-		return allow;
-	}
-
-	/* allow stop (drain) if input port is streaming */
-	if (is_state(inst, MSM_VIDC_INPUT_STREAMING) ||
-		is_state(inst, MSM_VIDC_STREAMING)) {
-		/* do not allow back to back drain */
-		if (!(is_sub_state(inst, MSM_VIDC_DRAIN)))
-			allow = MSM_VIDC_ALLOW;
-	} else if (is_state(inst, MSM_VIDC_OPEN)) {
-		allow = MSM_VIDC_IGNORE;
-		i_vpr_e(inst, "%s: ignored in state %s, sub state %s\n",
-			__func__, state_name(inst->state), inst->sub_state_name);
-	} else {
-		i_vpr_e(inst, "%s: not allowed in state %s, sub state %s\n",
-			__func__, state_name(inst->state), inst->sub_state_name);
-	}
-
-	return allow;
-}
-
-bool msm_vidc_allow_start(struct msm_vidc_inst *inst)
-{
-	bool allow = false;
-
-	if (!inst) {
-		d_vpr_e("%s: invalid params\n", __func__);
-		return allow;
-	}
-
-	/* client would call start (resume) to complete DRC/drain sequence */
-	if (inst->state == MSM_VIDC_INPUT_STREAMING ||
-		inst->state == MSM_VIDC_OUTPUT_STREAMING ||
-		inst->state == MSM_VIDC_STREAMING) {
-		if ((is_sub_state(inst, MSM_VIDC_DRC) &&
-			is_sub_state(inst, MSM_VIDC_DRC_LAST_BUFFER)) ||
-			(is_sub_state(inst, MSM_VIDC_DRAIN) &&
-			is_sub_state(inst, MSM_VIDC_DRAIN_LAST_BUFFER)))
-			allow = true;
-	}
-	if (!allow)
-		i_vpr_e(inst, "%s: not allowed in state %s, sub state %s\n",
-			__func__, state_name(inst->state), inst->sub_state_name);
-	return allow;
-}
-
-bool msm_vidc_allow_streamon(struct msm_vidc_inst *inst, u32 type)
-{
-	if (!inst) {
-		d_vpr_e("%s: invalid params\n", __func__);
-		return false;
-	}
-	if (type == INPUT_MPLANE || type == INPUT_META_PLANE) {
-		if (is_state(inst, MSM_VIDC_OPEN) ||
-			is_state(inst, MSM_VIDC_OUTPUT_STREAMING))
-			return true;
-	} else if (type == OUTPUT_MPLANE || type == OUTPUT_META_PLANE) {
-		if (is_state(inst, MSM_VIDC_OPEN) ||
-			is_state(inst, MSM_VIDC_INPUT_STREAMING))
-			return true;
-	}
-
-	i_vpr_e(inst, "%s: type %d not allowed in state %s\n",
-			__func__, type, state_name(inst->state));
-	return false;
-}
-
 enum msm_vidc_allow msm_vidc_allow_input_psc(struct msm_vidc_inst *inst)
 {
 	enum msm_vidc_allow allow = MSM_VIDC_ALLOW;
diff --git a/driver/vidc/src/msm_vidc_state.c b/driver/vidc/src/msm_vidc_state.c
index 698309848c..ec9d30bcd2 100644
--- a/driver/vidc/src/msm_vidc_state.c
+++ b/driver/vidc/src/msm_vidc_state.c
@@ -24,6 +24,18 @@ bool is_core_state(struct msm_vidc_core *core, enum msm_vidc_core_state state)
 	return core->state == state;
 }
 
+bool is_drc_pending(struct msm_vidc_inst *inst)
+{
+	return is_sub_state(inst, MSM_VIDC_DRC) &&
+		is_sub_state(inst, MSM_VIDC_DRC_LAST_BUFFER);
+}
+
+bool is_drain_pending(struct msm_vidc_inst *inst)
+{
+	return is_sub_state(inst, MSM_VIDC_DRAIN) &&
+		is_sub_state(inst, MSM_VIDC_DRAIN_LAST_BUFFER);
+}
+
 static const char * const core_state_name_arr[] =
 	FOREACH_CORE_STATE(GENERATE_STRING);
 
@@ -648,6 +660,7 @@ static int msm_vidc_open_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_format *f = (struct v4l2_format *)data;
 
+		/* allow s_fmt request in open state */
 		rc = msm_vidc_s_fmt(inst, f);
 		if (rc)
 			return rc;
@@ -667,6 +680,7 @@ static int msm_vidc_open_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_requestbuffers *b = (struct v4l2_requestbuffers *)data;
 
+		/* allow reqbufs request in open state */
 		rc = msm_vidc_reqbufs(inst, b);
 		if (rc)
 			return rc;
@@ -676,6 +690,7 @@ static int msm_vidc_open_state(struct msm_vidc_inst *inst,
 	{
 		struct vb2_queue *q = (struct vb2_queue *)data;
 
+		/* allow streamon request in open state */
 		rc = msm_vidc_start_streaming(inst, q);
 		if (rc)
 			return rc;
@@ -692,16 +707,17 @@ static int msm_vidc_open_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_START:
 	{
-		rc = msm_vidc_start_cmd(inst);
-		if (rc)
-			return rc;
-		break;
+		/* disallow start cmd request in open state */
+		i_vpr_e(inst, "%s: (%s) not allowed, sub_state (%s)\n",
+			__func__, event_name(event), inst->sub_state_name);
+
+		return -EBUSY;
 	}
 	case MSM_VIDC_CMD_STOP:
 	{
-		rc = msm_vidc_stop_cmd(inst);
-		if (rc)
-			return rc;
+		/* ignore stop cmd request in open state */
+		i_vpr_h(inst, "%s: (%s) ignored, sub_state (%s)\n",
+			__func__, event_name(event), inst->sub_state_name);
 		break;
 	}
 	case MSM_VIDC_BUF_QUEUE:
@@ -771,6 +787,13 @@ static int msm_vidc_input_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_format *f = (struct v4l2_format *)data;
 
+		/* disallow */
+		if (f->type == INPUT_MPLANE || f->type == INPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) port\n",
+				__func__, event_name(event), v4l2_type_name(f->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_s_fmt(inst, f);
 		if (rc)
 			return rc;
@@ -805,6 +828,13 @@ static int msm_vidc_input_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_requestbuffers *b = (struct v4l2_requestbuffers *)data;
 
+		/* disallow */
+		if (b->type == INPUT_MPLANE || b->type == INPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) port\n",
+				__func__, event_name(event), v4l2_type_name(b->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_reqbufs(inst, b);
 		if (rc)
 			return rc;
@@ -814,6 +844,13 @@ static int msm_vidc_input_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct vb2_queue *q = (struct vb2_queue *)data;
 
+		/* disallow */
+		if (q->type == INPUT_MPLANE || q->type == INPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) type\n",
+				__func__, event_name(event), v4l2_type_name(q->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_start_streaming(inst, q);
 		if (rc)
 			return rc;
@@ -850,6 +887,14 @@ static int msm_vidc_input_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_START:
 	{
+		/* disallow if START called for non DRC/drain cases */
+		if (!is_drc_pending(inst) && !is_drain_pending(inst)) {
+			i_vpr_e(inst, "%s: (%s) not allowed, sub_state (%s)\n",
+				__func__, event_name(event), inst->sub_state_name);
+			return -EBUSY;
+		}
+
+		/* client would call start(resume) to complete DRC/drain sequence */
 		rc = msm_vidc_start_cmd(inst);
 		if (rc)
 			return rc;
@@ -857,6 +902,13 @@ static int msm_vidc_input_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_STOP:
 	{
+		/* back to back drain not allowed */
+		if (is_sub_state(inst, MSM_VIDC_DRAIN)) {
+			i_vpr_e(inst, "%s: drain (%s) not allowed, sub_state (%s)\n\n",
+				__func__, event_name(event), inst->sub_state_name);
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_stop_cmd(inst);
 		if (rc)
 			return rc;
@@ -921,6 +973,13 @@ static int msm_vidc_output_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_format *f = (struct v4l2_format *)data;
 
+		/* disallow */
+		if (f->type == OUTPUT_MPLANE || f->type == OUTPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) port\n",
+				__func__, event_name(event), v4l2_type_name(f->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_s_fmt(inst, f);
 		if (rc)
 			return rc;
@@ -955,6 +1014,13 @@ static int msm_vidc_output_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct v4l2_requestbuffers *b = (struct v4l2_requestbuffers *)data;
 
+		/* disallow */
+		if (b->type == OUTPUT_MPLANE || b->type == OUTPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) port\n",
+				__func__, event_name(event), v4l2_type_name(b->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_reqbufs(inst, b);
 		if (rc)
 			return rc;
@@ -964,6 +1030,13 @@ static int msm_vidc_output_streaming_state(struct msm_vidc_inst *inst,
 	{
 		struct vb2_queue *q = (struct vb2_queue *)data;
 
+		/* disallow */
+		if (q->type == OUTPUT_MPLANE || q->type == OUTPUT_META_PLANE) {
+			i_vpr_e(inst, "%s: (%s) not allowed for (%s) type\n",
+				__func__, event_name(event), v4l2_type_name(q->type));
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_start_streaming(inst, q);
 		if (rc)
 			return rc;
@@ -1000,6 +1073,14 @@ static int msm_vidc_output_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_START:
 	{
+		/* disallow if START called for non DRC/drain cases */
+		if (!is_drc_pending(inst) && !is_drain_pending(inst)) {
+			i_vpr_e(inst, "%s: (%s) not allowed, sub_state (%s)\n",
+				__func__, event_name(event), inst->sub_state_name);
+			return -EBUSY;
+		}
+
+		/* client would call start(resume) to complete DRC/drain sequence */
 		rc = msm_vidc_start_cmd(inst);
 		if (rc)
 			return rc;
@@ -1007,10 +1088,10 @@ static int msm_vidc_output_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_STOP:
 	{
-		rc = msm_vidc_stop_cmd(inst);
-		if (rc)
-			return rc;
-		break;
+		/* drain not allowed as input is not streaming */
+		i_vpr_e(inst, "%s: drain (%s) not allowed, sub state %s\n",
+			__func__, event_name(event), inst->sub_state_name);
+		return -EBUSY;
 	}
 	default: {
 		i_vpr_e(inst, "%s: unexpected event %s\n", __func__, event_name(event));
@@ -1106,6 +1187,14 @@ static int msm_vidc_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_START:
 	{
+		/* disallow if START called for non DRC/drain cases */
+		if (!is_drc_pending(inst) && !is_drain_pending(inst)) {
+			i_vpr_e(inst, "%s: (%s) not allowed, sub_state (%s)\n",
+				__func__, event_name(event), inst->sub_state_name);
+			return -EBUSY;
+		}
+
+		/* client would call start(resume) to complete DRC/drain sequence */
 		rc = msm_vidc_start_cmd(inst);
 		if (rc)
 			return rc;
@@ -1113,6 +1202,13 @@ static int msm_vidc_streaming_state(struct msm_vidc_inst *inst,
 	}
 	case MSM_VIDC_CMD_STOP:
 	{
+		/* back to back drain not allowed */
+		if (is_sub_state(inst, MSM_VIDC_DRAIN)) {
+			i_vpr_e(inst, "%s: drain (%s) not allowed, sub_state (%s)\n\n",
+				__func__, event_name(event), inst->sub_state_name);
+			return -EBUSY;
+		}
+
 		rc = msm_vidc_stop_cmd(inst);
 		if (rc)
 			return rc;
diff --git a/driver/vidc/src/msm_vidc_vb2.c b/driver/vidc/src/msm_vidc_vb2.c
index 26ce6916a0..fb853ac11c 100644
--- a/driver/vidc/src/msm_vidc_vb2.c
+++ b/driver/vidc/src/msm_vidc_vb2.c
@@ -415,9 +415,6 @@ int msm_vidc_start_streaming(struct msm_vidc_inst *inst, struct vb2_queue *q)
 		return -EINVAL;
 	}
 
-	if (!msm_vidc_allow_streamon(inst, q->type))
-		return -EBUSY;
-
 	if (q->type == INPUT_META_PLANE || q->type == OUTPUT_META_PLANE) {
 		i_vpr_h(inst, "%s: nothing to start on %s\n",
 			__func__, v4l2_type_name(q->type));