Index: www/firefox/Makefile
===================================================================
--- www/firefox/Makefile
+++ www/firefox/Makefile
@@ -3,7 +3,7 @@
 
 PORTNAME=	firefox
 DISTVERSION=	80.0.1
-PORTEPOCH=	1
+PORTEPOCH=	2
 CATEGORIES=	www
 MASTER_SITES=	MOZILLA/${PORTNAME}/releases/${DISTVERSION}/source \
 		MOZILLA/${PORTNAME}/candidates/${DISTVERSION}-candidates/build1/source
Index: www/firefox/files/patch-dom_media_AudioStream.cpp
===================================================================
--- /dev/null
+++ www/firefox/files/patch-dom_media_AudioStream.cpp
@@ -0,0 +1,55 @@
+--- dom/media/AudioStream.cpp.orig	2020-09-02 19:01:19.287101000 +0800
++++ dom/media/AudioStream.cpp	2020-09-02 23:05:54.175619000 +0800
+@@ -582,8 +582,7 @@ void AudioStream::GetTimeStretched(AudioBufferWriter& 
+ bool AudioStream::CheckThreadIdChanged() {
+ #ifdef MOZ_GECKO_PROFILER
+   auto id = profiler_current_thread_id();
+-  if (id != mAudioThreadId) {
+-    mAudioThreadId = id;
++  if (id != mAudioThreadId.exchange(id, std::memory_order_acquire)) {
+     return true;
+   }
+ #endif
+@@ -591,7 +590,8 @@ bool AudioStream::CheckThreadIdChanged() {
+ }
+ 
+ long AudioStream::DataCallback(void* aBuffer, long aFrames) {
+-  if (!mSandboxed && CheckThreadIdChanged()) {
++  bool threadIdChanged = false;
++  if (!mSandboxed && (threadIdChanged = CheckThreadIdChanged())) {
+     CubebUtils::GetAudioThreadRegistry()->Register(mAudioThreadId);
+   }
+   WebCore::DenormalDisabler disabler;
+@@ -649,9 +649,12 @@ long AudioStream::DataCallback(void* aBuffer, long aFr
+   mDumpFile.Write(static_cast<const AudioDataValue*>(aBuffer),
+                   aFrames * mOutChannels);
+ 
+-  if (!mSandboxed && writer.Available() != 0) {
++#ifdef MOZ_GECKO_PROFILER
++  if (!mSandboxed && writer.Available() != 0 && !threadIdChanged) {
+     CubebUtils::GetAudioThreadRegistry()->Unregister(mAudioThreadId);
++    mAudioThreadId.store(0, std::memory_order_release);
+   }
++#endif
+   return aFrames - writer.Available();
+ }
+ 
+@@ -667,6 +670,18 @@ void AudioStream::StateCallback(cubeb_state aState) {
+     mState = ERRORED;
+     mDataSource.Errored();
+   }
++
++#ifdef MOZ_GECKO_PROFILER
++  if (!mSandboxed && aState != CUBEB_STATE_STARTED) {
++    // If DataCallback and this Callback stay on the same thread, in case the
++    // stream stopped for whatever reason, unregister the audio thread from
++    // audio thread registry.
++    int threadId = profiler_current_thread_id();
++    if (mAudioThreadId.compare_exchange_strong(threadId, 0)) {
++      CubebUtils::GetAudioThreadRegistry()->Unregister(threadId);
++    }
++  }
++#endif
+ }
+ 
+ AudioClock::AudioClock()