Precise delay broken whenever beyond precise duration. (#264)

* Precise delay broken whenever beyond precise duration. * Fix lazy delay for interrupt sensitive applications
plerup · Dec 10, 2022 · 12f8480 · 12f8480
1 parent 8d9d01e
commit 12f8480
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Showing 3 changed files with 7 additions and 4 deletions.
diff --git a/library.json b/library.json
@@ -1,6 +1,6 @@
 {
  "name": "EspSoftwareSerial",
- "version": "6.17.0",
+ "version": "6.17.1",
  "description": "Implementation of the Arduino software serial for ESP8266/ESP32.",
  "keywords": [
  "serial", "io", "softwareserial"

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=EspSoftwareSerial
-version=6.17.0
+version=6.17.1
 author=Dirk Kaar, Peter Lerup
 maintainer=Dirk Kaar <dok@dok-net.net>
 sentence=Implementation of the Arduino software serial for ESP8266/ESP32.

diff --git a/src/SoftwareSerial.cpp b/src/SoftwareSerial.cpp
@@ -351,16 +351,19 @@ void SoftwareSerial::lazyDelay() {
  {
  optimistic_yield(10000UL);
  }
+ // Assure that below-ms part of delays are not elided
+ preciseDelay();
  // Disable interrupts again if applicable
  if (!m_intTxEnabled) { disableInterrupts(); }
- preciseDelay();
 }
 
 void IRAM_ATTR SoftwareSerial::preciseDelay() {
  uint32_t ticks;
+ uint32_t expired;
  do {
  ticks = microsToTicks(micros());
- } while ((ticks - m_periodStart) < m_periodDuration);
+ expired = ticks - m_periodStart;
+ } while (static_cast<int32_t>(m_periodDuration - expired) > 0);
  m_periodDuration = 0;
  m_periodStart = ticks;
 }