From 7d2d7532522971bcdd6f018469d2e8b16b8160c0 Mon Sep 17 00:00:00 2001
From: Verkehrsrot <cyberman@obh.snafu.de>
Date: Tue, 23 Jul 2019 17:53:20 +0200
Subject: [PATCH] bugfixing mutex lock

---
 src/display.cpp    | 10 ++++++----
 src/irqhandler.cpp | 11 ++++++-----
 src/timesync.cpp   |  2 +-
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/display.cpp b/src/display.cpp
index 260686fe..632e0ee8 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -62,8 +62,9 @@ void DisplayKey(const uint8_t *key, uint8_t len, bool lsb) {
 void init_display(const char *Productname, const char *Version) {
 
   // block i2c bus access
-  if (I2C_MUTEX_LOCK()) {
-
+  if (!I2C_MUTEX_LOCK())
+    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
+  else {
     // show startup screen
     uint8_t buf[32];
     u8x8.begin();
@@ -141,8 +142,9 @@ void refreshTheDisplay(bool nextPage) {
       myTZ.toLocal(now()); // note: call now() here *before* locking mutex!
 
   // block i2c bus access
-  if (I2C_MUTEX_LOCK()) {
-
+  if (!I2C_MUTEX_LOCK())
+    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
+  else {
     // set display on/off according to current device configuration
     if (DisplayIsOn != cfg.screenon) {
       DisplayIsOn = cfg.screenon;
diff --git a/src/irqhandler.cpp b/src/irqhandler.cpp
index f95f6fe9..1ecfa59f 100644
--- a/src/irqhandler.cpp
+++ b/src/irqhandler.cpp
@@ -120,12 +120,13 @@ void IRAM_ATTR GpsIRQ() {
 #endif
 
 int mask_user_IRQ() {
-  // begin of time critical section: lock I2C bus to ensure accurate timing
-  if (I2C_MUTEX_LOCK()) {
+  if (!I2C_MUTEX_LOCK()) {
+    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
+    return 0; // failure
+  } else {
     xTaskNotify(irqHandlerTask, MASK_IRQ, eSetBits);
-    return 0;
-  } else
-    return 1; // failure
+    return 1; // success
+  }
 }
 
 int unmask_user_IRQ() {
diff --git a/src/timesync.cpp b/src/timesync.cpp
index 42cdecd9..ec85370b 100644
--- a/src/timesync.cpp
+++ b/src/timesync.cpp
@@ -113,7 +113,7 @@ void process_timesync_req(void *taskparameter) {
     // begin of time critical section: lock app irq's and I2C bus
     if (!mask_user_IRQ()) {
       ESP_LOGW(TAG,
-               "[%0.3f] Timesync handshake error: irq / i2c masking failed",
+               "[%0.3f] Timesync handshake error: irq masking failed",
                millis() / 1000.0);
       goto finish; // failure
     }