From 0fbb76accf446e1b54c77c723ca41d6b4308a432 Mon Sep 17 00:00:00 2001
From: "Dirk O. Kaar" <dok@dok-net.net>
Date: Sun, 1 Sep 2019 19:59:42 +0200
Subject: [PATCH 1/2] Inline ESP::getCycleCount() to make it safe to call from
 ISRs

---
 cores/esp32/Esp.cpp | 7 -------
 cores/esp32/Esp.h   | 9 ++++++++-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/cores/esp32/Esp.cpp b/cores/esp32/Esp.cpp
index 8df9514ee66..54451127ef3 100644
--- a/cores/esp32/Esp.cpp
+++ b/cores/esp32/Esp.cpp
@@ -92,13 +92,6 @@ void EspClass::deepSleep(uint32_t time_us)
     esp_deep_sleep(time_us);
 }
 
-uint32_t EspClass::getCycleCount()
-{
-    uint32_t ccount;
-    __asm__ __volatile__("esync; rsr %0,ccount":"=a" (ccount));
-    return ccount;
-}
-
 void EspClass::restart(void)
 {
     esp_restart();
diff --git a/cores/esp32/Esp.h b/cores/esp32/Esp.h
index 9acb6665c3d..60470aacf2c 100644
--- a/cores/esp32/Esp.h
+++ b/cores/esp32/Esp.h
@@ -76,7 +76,7 @@ class EspClass
 
     uint8_t getChipRevision();
     uint32_t getCpuFreqMHz(){ return getCpuFrequencyMhz(); }
-    uint32_t getCycleCount();
+    inline uint32_t getCycleCount() __attribute__((always_inline));
     const char * getSdkVersion();
 
     void deepSleep(uint32_t time_us);
@@ -101,6 +101,13 @@ class EspClass
 
 };
 
+uint32_t EspClass::getCycleCount()
+{
+    uint32_t ccount;
+    __asm__ __volatile__("esync; rsr %0,ccount":"=a" (ccount));
+    return ccount;
+}
+
 extern EspClass ESP;
 
 #endif //ESP_H

From 9f3e75d35285a607f51c510f4b7a6165c7525e31 Mon Sep 17 00:00:00 2001
From: "Dirk O. Kaar" <dok@dok-net.net>
Date: Tue, 10 Sep 2019 23:42:32 +0200
Subject: [PATCH 2/2] Attribute IRAM_ATTR ISR-safe function in addition to
 inlining.

---
 cores/esp32/Esp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cores/esp32/Esp.h b/cores/esp32/Esp.h
index 60470aacf2c..2580eecf65b 100644
--- a/cores/esp32/Esp.h
+++ b/cores/esp32/Esp.h
@@ -101,7 +101,7 @@ class EspClass
 
 };
 
-uint32_t EspClass::getCycleCount()
+uint32_t IRAM_ATTR EspClass::getCycleCount()
 {
     uint32_t ccount;
     __asm__ __volatile__("esync; rsr %0,ccount":"=a" (ccount));