diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index 5c51607d..93b700bd 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -509,6 +509,13 @@ void IPAIPU3::unmapBuffers(const std::vector<unsigned int> &ids)
 /**
  * \brief Process an event generated by the pipeline handler
  * \param[in] event The event sent from pipeline handler
+ *
+ * The expected event handling over the lifetime of a Request has
+ * the following sequence:
+ *
+ *   - EventProcessControls : Handle controls from a new Request
+ *   - EventFillParams : Prepare the ISP to process the Request
+ *   - EventStatReady : Process statistics after ISP completion
  */
 void IPAIPU3::processEvent(const IPU3Event &event)
 {
@@ -517,20 +524,6 @@ void IPAIPU3::processEvent(const IPU3Event &event)
 		processControls(event.frame, event.controls);
 		break;
 	}
-	case EventStatReady: {
-		auto it = buffers_.find(event.bufferId);
-		if (it == buffers_.end()) {
-			LOG(IPAIPU3, Error) << "Could not find stats buffer!";
-			return;
-		}
-
-		Span<uint8_t> mem = it->second.planes()[0];
-		const ipu3_uapi_stats_3a *stats =
-			reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
-
-		parseStatistics(event.frame, event.frameTimestamp, stats);
-		break;
-	}
 	case EventFillParams: {
 		auto it = buffers_.find(event.bufferId);
 		if (it == buffers_.end()) {
@@ -545,6 +538,20 @@ void IPAIPU3::processEvent(const IPU3Event &event)
 		fillParams(event.frame, params);
 		break;
 	}
+	case EventStatReady: {
+		auto it = buffers_.find(event.bufferId);
+		if (it == buffers_.end()) {
+			LOG(IPAIPU3, Error) << "Could not find stats buffer!";
+			return;
+		}
+
+		Span<uint8_t> mem = it->second.planes()[0];
+		const ipu3_uapi_stats_3a *stats =
+			reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
+
+		parseStatistics(event.frame, event.frameTimestamp, stats);
+		break;
+	}
 	default:
 		LOG(IPAIPU3, Error) << "Unknown event " << event.op;
 		break;