From 410391598ece7d0eea195129d13197a5587df488 Mon Sep 17 00:00:00 2001
From: rusefi <rusefillc@gmail.com>
Date: Sun, 10 Nov 2019 23:54:08 -0500
Subject: [PATCH] Strange INJ1 signal behavior (when the frequency of
 scheduler's timer is less than 1MHz) fix #996

---
 firmware/controllers/algo/obd_error_codes.h |  4 +-
 firmware/controllers/engine_controller.cpp  |  2 +-
 firmware/hw_layer/microsecond_timer.cpp     | 44 +++++++++++++++++++++
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/firmware/controllers/algo/obd_error_codes.h b/firmware/controllers/algo/obd_error_codes.h
index f38b27e818..92dd57942d 100644
--- a/firmware/controllers/algo/obd_error_codes.h
+++ b/firmware/controllers/algo/obd_error_codes.h
@@ -2070,8 +2070,8 @@ typedef enum {
 	CUSTOM_ERR_BOTH_FRONTS_REQUIRED = 6704,
 	CUSTOM_TLE8888 = 6705,
 	CUSTOM_ERR_6706 = 6706,
-	CUSTOM_ERR_6707 = 6707,
-	CUSTOM_ERR_6708 = 6708,
+	CUSTOM_ERR_TIMER_TEST_CALLBACK_NOT_HAPPENED = 6707,
+	CUSTOM_ERR_TIMER_TEST_CALLBACK_WRONG_TIME = 6708,
 	CUSTOM_ERR_PIN_COUNT_TOO_LARGE = 6709,
 	CUSTOM_DUTY_INVALID = 6710,
 	CUSTOM_DUTY_TOO_HIGH = 6711,
diff --git a/firmware/controllers/engine_controller.cpp b/firmware/controllers/engine_controller.cpp
index f6a64ffe8b..b92ccbc981 100644
--- a/firmware/controllers/engine_controller.cpp
+++ b/firmware/controllers/engine_controller.cpp
@@ -839,6 +839,6 @@ int getRusEfiVersion(void) {
 	if (initBootloader() != 0)
 		return 123;
 #endif /* EFI_BOOTLOADER_INCLUDE_CODE */
-	return 20191109;
+	return 20191110;
 }
 #endif /* EFI_UNIT_TEST */
diff --git a/firmware/hw_layer/microsecond_timer.cpp b/firmware/hw_layer/microsecond_timer.cpp
index 526f4a90be..9309c5f6e5 100644
--- a/firmware/hw_layer/microsecond_timer.cpp
+++ b/firmware/hw_layer/microsecond_timer.cpp
@@ -25,6 +25,14 @@
 #include "engine.h"
 EXTERN_ENGINE;
 
+// Just in case we have a mechanism to validate that hardware timer is clocked right and all the
+// conversions between wall clock and hardware frequencies are done right
+// delay in milliseconds
+#define TEST_CALLBACK_DELAY 30
+// if hardware timer is 20% off we throw a fatal error and call it a day
+// maybe this threshold should be 5%? 10%?
+#define TIMER_PRECISION_THRESHOLD 0.2
+
 /**
  * Maximum duration of complete timer callback, all pending events together
  * See also 'maxEventCallbackDuration' for maximum duration of one event
@@ -142,6 +150,10 @@ class MicrosecondTimerWatchdogController : public PeriodicTimerController {
 
 static MicrosecondTimerWatchdogController watchdogControllerInstance;
 
+/*
+ * The specific 1MHz frequency is important here since 'setHardwareUsTimer' method takes microsecond parameter
+ * For any arbitrary frequency to work we would need an additional layer of conversion.
+ */
 static constexpr GPTConfig gpt5cfg = { 1000000, /* 1 MHz timer clock.*/
 		hwTimerCallback, /* Timer callback.*/
 0, 0 };
@@ -158,6 +170,36 @@ static void watchDogBuddyCallback(void *arg) {
 	engine->executor.scheduleForLater(&watchDogBuddy, MS2US(1000), watchDogBuddyCallback, NULL);
 }
 
+static volatile bool testSchedulingHappened = false;
+static efitimems_t testSchedulingStart;
+
+static void timerValidationCallback(void *arg) {
+	(void)arg;
+
+	testSchedulingHappened = true;
+	efitimems_t actualTimeSinceScheduling = (currentTimeMillis() - testSchedulingStart);
+
+	if (absI(actualTimeSinceScheduling - TEST_CALLBACK_DELAY) > TEST_CALLBACK_DELAY * TIMER_PRECISION_THRESHOLD) {
+		firmwareError(CUSTOM_ERR_TIMER_TEST_CALLBACK_WRONG_TIME, "hwTimer broken precision");
+	}
+}
+
+/**
+ * This method would validate that hardware timer callbacks happen with some reasonable precision
+ * helps to make sure our GPT hardware settings are somewhat right
+ */
+static void validateHardwareTimer() {
+	testSchedulingStart = currentTimeMillis();
+
+	// to save RAM let's use 'watchDogBuddy' here once before we enable watchdog
+	engine->executor.scheduleForLater(&watchDogBuddy, MS2US(TEST_CALLBACK_DELAY), timerValidationCallback, NULL);
+
+	chThdSleepMilliseconds(2 * TEST_CALLBACK_DELAY);
+	if (!testSchedulingHappened) {
+		firmwareError(CUSTOM_ERR_TIMER_TEST_CALLBACK_NOT_HAPPENED, "hwTimer not alive");
+	}
+}
+
 void initMicrosecondTimer(void) {
 
 	gptStart(&GPTDEVICE, &gpt5cfg);
@@ -166,6 +208,8 @@ void initMicrosecondTimer(void) {
 
 	lastSetTimerTimeNt = getTimeNowNt();
 
+	validateHardwareTimer();
+
 	watchDogBuddyCallback(NULL);
 #if EFI_EMULATE_POSITION_SENSORS
 	watchdogControllerInstance.Start();