inhibit sensor timeout during flash (#3146)

* inhibit timeout during flash

* do it up a level

Co-authored-by: Matthew Kennedy <makenne@microsoft.com>

firmware/controllers/flash_main.cpp

@@ -116,9 +116,13 @@ void writeToFlashIfPending() {
 	// with a flash write thread, the schedule happens directly from
 	// setNeedToWriteConfiguration, so there's nothing to do here
 	if (allowFlashWhileRunning() || !getNeedToWriteConfiguration()) {
+		// Allow sensor timeouts again now that we're done (and a little time has passed)
+		Sensor::inhibitTimeouts(false);
 		return;
 	}
 
+	// Prevent sensor timeouts while flashing
+	Sensor::inhibitTimeouts(true);
 	writeToFlashNow();
 }
 

firmware/controllers/sensors/sensor.cpp

@@ -261,6 +261,12 @@ bool Sensor::Register() {
 	return s_sensorNames[static_cast<size_t>(type)];
 }
 
+/*static*/ bool Sensor::s_inhibitSensorTimeouts = false;
+
+/*static*/ void Sensor::inhibitTimeouts(bool inhibit) {
+	Sensor::s_inhibitSensorTimeouts = inhibit;
+}
+
 // Print information about all sensors
 /*static*/ void Sensor::showAllSensorInfo() {
 	for (size_t i = 1; i < efi::size(s_sensorRegistry); i++) {

firmware/controllers/sensors/sensor.h

@@ -121,6 +121,12 @@ public:
 	 */
 	static void resetAllMocks();
 
+	/*
+	 * Inhibit sensor timeouts. Used if you're doing something that will block sensor updates, such as 
+	 * erasing flash memory (which stalls the CPU on some MCUs)
+	 */
+	static void inhibitTimeouts(bool inhibit);
+
 	/*
 	 * Get a friendly name for the sensor.
 	 * For example, CLT, IAT, Throttle Position 2, etc.
@@ -160,6 +166,8 @@ protected:
 	explicit Sensor(SensorType type)
 		: m_type(type) {}
 
+	static bool s_inhibitSensorTimeouts;
+
 private:
 	const SensorType m_type;
 

firmware/controllers/sensors/stored_value_sensor.h

@@ -37,6 +37,11 @@ public:
 			return unexpected;
 		}
 
+		// Timeouts are disabled, return last value
+		if (Sensor::s_inhibitSensorTimeouts) {
+			return value;
+		}
+
 		if (m_timeoutPeriod != 0) { // zero m_timeoutPeriod means value lasts forever
 			if (getTimeNowNt() - m_timeoutPeriod > m_lastUpdate) {
 				return unexpected;