diff --git a/firmware/controllers/error_handling.cpp b/firmware/controllers/error_handling.cpp
index 11c1252252..8bf672c4dc 100644
--- a/firmware/controllers/error_handling.cpp
+++ b/firmware/controllers/error_handling.cpp
@@ -155,16 +155,19 @@ char *getWarning(void) {
 }
 
 uint32_t lastLockTime;
-uint32_t maxLockTime = 0;
+/**
+ * Maximum time before requesting lock and releasing lock at the end of critical section
+ */
+uint32_t maxLockedDuration = 0;
 
 void onLockHook(void) {
 	lastLockTime = GET_TIMESTAMP();
 }
 
 void onUnlockHook(void) {
-	uint32_t t = GET_TIMESTAMP() - lastLockTime;
-	if (t > maxLockTime) {
-		maxLockTime = t;
+	uint32_t lockedDuration = GET_TIMESTAMP() - lastLockTime;
+	if (lockedDuration > maxLockedDuration) {
+		maxLockedDuration = lockedDuration;
 	}
 //	if (t > 2800) {
 //		// un-comment this if you want a nice stop for a breakpoint
diff --git a/firmware/controllers/system/SingleTimerExecutor.cpp b/firmware/controllers/system/SingleTimerExecutor.cpp
index dfa58f0759..def902afdd 100644
--- a/firmware/controllers/system/SingleTimerExecutor.cpp
+++ b/firmware/controllers/system/SingleTimerExecutor.cpp
@@ -35,8 +35,7 @@ extern schfunc_t globalTimerCallback;
  */
 static efitime_t nextEventTimeNt = 0;
 
-uint32_t beforeHwSetTimer;
-uint32_t hwSetTimerTime;
+uint32_t hwSetTimerDuration;
 uint32_t lastExecutionCount;
 
 static void executorCallback(void *arg) {
@@ -136,9 +135,9 @@ void Executor::scheduleTimerCallback() {
 	if (nextEventTimeNt == EMPTY_QUEUE)
 		return; // no pending events in the queue
 	int32_t hwAlarmTime = NT2US((int32_t)nextEventTimeNt - (int32_t)nowNt);
-	beforeHwSetTimer = GET_TIMESTAMP();
+	uint32_t beforeHwSetTimer = GET_TIMESTAMP();
 	setHardwareUsTimer(hwAlarmTime == 0 ? 1 : hwAlarmTime);
-	hwSetTimerTime = GET_TIMESTAMP() - beforeHwSetTimer;
+	hwSetTimerDuration = GET_TIMESTAMP() - beforeHwSetTimer;
 }
 
 /**
diff --git a/firmware/controllers/system/event_queue.cpp b/firmware/controllers/system/event_queue.cpp
index bcff3d9f52..914081b7ce 100644
--- a/firmware/controllers/system/event_queue.cpp
+++ b/firmware/controllers/system/event_queue.cpp
@@ -106,8 +106,11 @@ efitime_t EventQueue::getNextEventTime(efitime_t nowX) {
 }
 
 static scheduling_s * longScheduling;
-uint32_t maxEventQueueTime = 0;
-uint32_t lastEventQueueTime;
+/**
+ * See also maxPrecisionCallbackDuration for total hw callback time
+ */
+uint32_t maxEventCallbackDuration = 0;
+static uint32_t lastEventCallbackDuration;
 
 /**
  * Invoke all pending actions prior to specified timestamp
@@ -169,12 +172,12 @@ int EventQueue::executeAll(efitime_t now) {
 #endif
 		current->callback(current->param);
 		// even with overflow it's safe to subtract here
-		lastEventQueueTime = GET_TIMESTAMP() - before;
-		if (lastEventQueueTime > maxEventQueueTime)
-			maxEventQueueTime = lastEventQueueTime;
-		if (lastEventQueueTime > 2000) {
+		lastEventCallbackDuration = GET_TIMESTAMP() - before;
+		if (lastEventCallbackDuration > maxEventCallbackDuration)
+			maxEventCallbackDuration = lastEventCallbackDuration;
+		if (lastEventCallbackDuration > 2000) {
 			longScheduling = current;
-			lastEventQueueTime++;
+// what is this line about?			lastEventCallbackDuration++;
 		}
 	}
 	return executionCounter;
diff --git a/firmware/controllers/trigger/trigger_central.cpp b/firmware/controllers/trigger/trigger_central.cpp
index a48479e59f..f5ac86aea9 100644
--- a/firmware/controllers/trigger/trigger_central.cpp
+++ b/firmware/controllers/trigger/trigger_central.cpp
@@ -386,11 +386,15 @@ void printAllTriggers() {
 extern PwmConfig triggerSignal;
 #endif /* #if EFI_PROD_CODE */
 
-extern uint32_t maxLockTime;
-extern uint32_t maxEventQueueTime;
 extern uint32_t hipLastExecutionCount;
-extern uint32_t hwSetTimerTime;
-extern uint32_t maxPrecisionTCallbackDuration;
+extern uint32_t hwSetTimerDuration;
+
+extern uint32_t maxLockedDuration;
+extern uint32_t maxEventCallbackDuration;
+
+#if (EFI_PROD_CODE) || defined(__DOXYGEN__)
+extern uint32_t maxPrecisionCallbackDuration;
+#endif /* EFI_PROD_CODE  */
 
 extern int maxHowFarOff;
 extern uint32_t *cyccnt;
@@ -400,9 +404,13 @@ extern int vvtEventFallCounter;
 
 void resetMaxValues() {
 #if (EFI_PROD_CODE || EFI_SIMULATOR) || defined(__DOXYGEN__)
-	maxEventQueueTime = triggerMaxDuration = 0;
-	maxPrecisionTCallbackDuration = 0;
+	maxEventCallbackDuration = triggerMaxDuration = 0;
 #endif /* EFI_PROD_CODE || EFI_SIMULATOR */
+	maxLockedDuration = 0;
+
+#if (EFI_PROD_CODE) || defined(__DOXYGEN__)
+	maxPrecisionCallbackDuration = 0;
+#endif /* EFI_PROD_CODE  */
 }
 
 void triggerInfo(void) {
@@ -495,15 +503,14 @@ void triggerInfo(void) {
 			engine->m.rpmCbTime,
 			engine->m.mainTriggerCallbackTime);
 
-	scheduleMsg(logger, "maxLockTime=%d / maxTriggerReentraint=%d", maxLockTime, maxTriggerReentraint);
-	maxLockTime = 0;
-	scheduleMsg(logger, "maxEventQueueTime=%d", maxEventQueueTime);
+	scheduleMsg(logger, "maxLockedDuration=%d / maxTriggerReentraint=%d", maxLockedDuration, maxTriggerReentraint);
+	scheduleMsg(logger, "maxEventCallbackDuration=%d", maxEventCallbackDuration);
 
 	scheduleMsg(logger, "hipLastExecutionCount=%d", hipLastExecutionCount);
-	scheduleMsg(logger, "hwSetTimerTime %d", hwSetTimerTime);
+	scheduleMsg(logger, "hwSetTimerDuration=%d", hwSetTimerDuration);
 
 	scheduleMsg(logger, "totalTriggerHandlerMaxTime=%d", triggerMaxDuration);
-	scheduleMsg(logger, "maxPrecisionTCallbackDuration=%d", maxPrecisionTCallbackDuration);
+	scheduleMsg(logger, "maxPrecisionCallbackDuration=%d", maxPrecisionCallbackDuration);
 	resetMaxValues();
 
 #endif /* EFI_PROD_CODE */
diff --git a/firmware/hw_layer/microsecond_timer.cpp b/firmware/hw_layer/microsecond_timer.cpp
index 37b3177dd5..e619fd01ce 100644
--- a/firmware/hw_layer/microsecond_timer.cpp
+++ b/firmware/hw_layer/microsecond_timer.cpp
@@ -21,8 +21,13 @@
 #if (EFI_PROD_CODE && HAL_USE_GPT) || defined(__DOXYGEN__)
 #include "efilib2.h"
 
-uint32_t maxPrecisionTCallbackDuration = 0;
+/**
+ * Maximum duration of complete timer callback, all pending events together
+ * See also 'maxEventCallbackDuration' for maximum duration of one event
+ */
+uint32_t maxPrecisionCallbackDuration = 0;
 
+// must be one of 32 bit times
 #define GPTDEVICE GPTD5
 
 static volatile efitick_t lastSetTimerTimeNt;
@@ -99,8 +104,8 @@ static void callback(GPTDriver *gptp) {
 	uint32_t before = GET_TIMESTAMP();
 	globalTimerCallback(NULL);
 	uint32_t precisionCallbackDuration = GET_TIMESTAMP() - before;
-	if (precisionCallbackDuration > maxPrecisionTCallbackDuration) {
-		maxPrecisionTCallbackDuration = precisionCallbackDuration;
+	if (precisionCallbackDuration > maxPrecisionCallbackDuration) {
+		maxPrecisionCallbackDuration = precisionCallbackDuration;
 	}
 }