AudioTrack: fix direct tracks not pausing

When a Direct Track is paused and the HAL does not support
pause() and resume() then the HW never gets paused.
The app can just keep writing data, which gets played.

Bug: 18899620
Change-Id: Ice0f360956ff7ca425f6f24a0a2a8640d8b43fa8
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 234e45f..1ca89a8 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -2055,6 +2055,9 @@
             ALOGW("direct output implements resume but not pause");
         }
     }
+    if (!mHwSupportsPause && mOutput->flags & AUDIO_OUTPUT_FLAG_HW_AV_SYNC) {
+        LOG_ALWAYS_FATAL("HW_AV_SYNC requested but HAL does not implement pause and resume");
+    }
 
     if (mType == DUPLICATING && mMixerBufferEnabled && mEffectBufferEnabled) {
         // For best precision, we use float instead of the associated output
@@ -4375,9 +4378,9 @@
         sp<Track> l = mLatestActiveTrack.promote();
         bool last = l.get() == track;
 
-        if (mHwSupportsPause && track->isPausing()) {
+        if (track->isPausing()) {
             track->setPaused();
-            if (last && !mHwPaused) {
+            if (mHwSupportsPause && last && !mHwPaused) {
                 doHwPause = true;
                 mHwPaused = true;
             }
@@ -4387,13 +4390,11 @@
             if (last) {
                 flushPending = true;
             }
-        } else if (mHwSupportsPause && track->isResumePending()){
+        } else if (track->isResumePending()) {
             track->resumeAck();
-            if (last) {
-                if (mHwPaused) {
-                    doHwResume = true;
-                    mHwPaused = false;
-                }
+            if (last && mHwPaused) {
+                doHwResume = true;
+                mHwPaused = false;
             }
         }
 
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 2c514f8..3898532 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -713,8 +713,9 @@
                                    audio_patch_handle_t *handle);
     virtual     status_t    releaseAudioPatch_l(const audio_patch_handle_t handle);
 
-                bool        usesHwAvSync() const { return (mType == DIRECT) && (mOutput != NULL) &&
-                                                (mOutput->flags & AUDIO_OUTPUT_FLAG_HW_AV_SYNC); }
+                bool        usesHwAvSync() const { return (mType == DIRECT) && (mOutput != NULL)
+                                    && mHwSupportsPause
+                                    && (mOutput->flags & AUDIO_OUTPUT_FLAG_HW_AV_SYNC); }
 
 private: