Fix issue 2929440

Fixed regression introduced by change a54d7d3d7dd691334189aab20d23c65710092869 in audioflinger mixer thread:
When the output stream is suspended, the sleep time between two writes must match the actual duration
of one output stream buffer otherwise the playback rate is not respected.

Change-Id: Ic5bebe890290d1f44aeff9dd3c142d18e26fff2a
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 6e7633e..ff31470 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -1601,7 +1601,7 @@
         }
 
         if (mSuspended) {
-            sleepTime = idleSleepTime;
+            sleepTime = suspendSleepTimeUs();
         }
         // sleepTime == 0 means we must write to audio hardware
         if (sleepTime == 0) {
@@ -2021,6 +2021,11 @@
     return (uint32_t)(((mFrameCount * 1000) / mSampleRate) * 1000) / 2;
 }
 
+uint32_t AudioFlinger::MixerThread::suspendSleepTimeUs()
+{
+    return (uint32_t)(((mFrameCount * 1000) / mSampleRate) * 1000);
+}
+
 // ----------------------------------------------------------------------------
 AudioFlinger::DirectOutputThread::DirectOutputThread(const sp<AudioFlinger>& audioFlinger, AudioStreamOut* output, int id, uint32_t device)
     :   PlaybackThread(audioFlinger, output, id, device)
@@ -2365,7 +2370,7 @@
         }
 
         if (mSuspended) {
-            sleepTime = idleSleepTime;
+            sleepTime = suspendSleepTimeUs();
         }
         // sleepTime == 0 means we must write to audio hardware
         if (sleepTime == 0) {
@@ -2486,6 +2491,18 @@
     return time;
 }
 
+uint32_t AudioFlinger::DirectOutputThread::suspendSleepTimeUs()
+{
+    uint32_t time;
+    if (AudioSystem::isLinearPCM(mFormat)) {
+        time = (uint32_t)(((mFrameCount * 1000) / mSampleRate) * 1000);
+    } else {
+        time = 10000;
+    }
+    return time;
+}
+
+
 // ----------------------------------------------------------------------------
 
 AudioFlinger::DuplicatingThread::DuplicatingThread(const sp<AudioFlinger>& audioFlinger, AudioFlinger::MixerThread* mainThread, int id)
@@ -2612,7 +2629,7 @@
         }
 
         if (mSuspended) {
-            sleepTime = idleSleepTime;
+            sleepTime = suspendSleepTimeUs();
         }
         // sleepTime == 0 means we must write to audio hardware
         if (sleepTime == 0) {
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 5520551..51881f0 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -664,6 +664,7 @@
         virtual void            deleteTrackName_l(int name) = 0;
         virtual uint32_t        activeSleepTimeUs() = 0;
         virtual uint32_t        idleSleepTimeUs() = 0;
+        virtual uint32_t        suspendSleepTimeUs() = 0;
 
     private:
 
@@ -724,6 +725,7 @@
         virtual     void        deleteTrackName_l(int name);
         virtual     uint32_t    activeSleepTimeUs();
         virtual     uint32_t    idleSleepTimeUs();
+        virtual     uint32_t    suspendSleepTimeUs();
 
         AudioMixer*                     mAudioMixer;
     };
@@ -744,6 +746,7 @@
         virtual     void        deleteTrackName_l(int name);
         virtual     uint32_t    activeSleepTimeUs();
         virtual     uint32_t    idleSleepTimeUs();
+        virtual     uint32_t    suspendSleepTimeUs();
 
     private:
         void applyVolume(uint16_t leftVol, uint16_t rightVol, bool ramp);