commit 42537be61479e59c4718e1304364551c1454f63c
author Eric Laurent <elaurent@google.com> Fri Jan 08 17:16:42 2016 -0800
committer Eric Laurent <elaurent@google.com> Mon Jan 11 16:20:17 2016 -0800
tree 6afec3010213d47681980d4c9ac0cda9aaa81cab
parent a3e696da3872250bca66a62d93a3b6114e20c27d

audioflinger: fix standby delay on A2DP output

Make sure that standby delay is never less than the audio flinger
default on A2DP output.
Due to variable latency and amount of buffering in A2DP sinks,
an agressive standby delay could lead to truncated audio.

Bug: 25830539.
Change-Id: I38be37ad346f5f4bf8303d3db4e3e911bf637968

services/audioflinger/Threads.cpp

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 381ce92..1769b0c 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1611,6 +1611,7 @@
     dprintf(fd, "  Mixer buffer: %p\n", mMixerBuffer);
     dprintf(fd, "  Effect buffer: %p\n", mEffectBuffer);
     dprintf(fd, "  Fast track availMask=%#x\n", mFastTrackAvailMask);
+    dprintf(fd, "  Standby delay ns=%lld\n", (long long)mStandbyDelayNs);
     AudioStreamOut *output = mOutput;
     audio_output_flags_t flags = output != NULL ? output->flags : AUDIO_OUTPUT_FLAG_NONE;
     String8 flagsAsString = outputFlagsToString(flags);
@@ -2535,7 +2536,8 @@
  - mSinkBufferSize from frame count * frame size
  - mActiveSleepTimeUs from activeSleepTimeUs()
  - mIdleSleepTimeUs from idleSleepTimeUs()
- - mStandbyDelayNs from mActiveSleepTimeUs (DIRECT only)
+ - mStandbyDelayNs from mActiveSleepTimeUs (DIRECT only) or forced to at least
+   kDefaultStandbyTimeInNsecs when connected to an A2DP device.
  - maxPeriod from frame count and sample rate (MIXER only)
 
 The parameters that affect these derived values are:
@@ -2554,6 +2556,15 @@
     mSinkBufferSize = mNormalFrameCount * mFrameSize;
     mActiveSleepTimeUs = activeSleepTimeUs();
     mIdleSleepTimeUs = idleSleepTimeUs();
+
+    // make sure standby delay is not too short when connected to an A2DP sink to avoid
+    // truncating audio when going to standby.
+    mStandbyDelayNs = AudioFlinger::mStandbyTimeInNsecs;
+    if ((mOutDevice & AUDIO_DEVICE_OUT_ALL_A2DP) != 0) {
+        if (mStandbyDelayNs < kDefaultStandbyTimeInNsecs) {
+            mStandbyDelayNs = kDefaultStandbyTimeInNsecs;
+        }
+    }
 }
 
 void AudioFlinger::PlaybackThread::invalidateTracks(audio_stream_type_t streamType)
@@ -4273,6 +4284,7 @@
                                                        status_t& status)
 {
     bool reconfig = false;
+    bool a2dpDeviceChanged = false;
 
     status = NO_ERROR;
 
@@ -4349,6 +4361,8 @@
         // forward device change to effects that have requested to be
         // aware of attached audio device.
         if (value != AUDIO_DEVICE_NONE) {
+            a2dpDeviceChanged =
+                    (mOutDevice & AUDIO_DEVICE_OUT_ALL_A2DP) != (value & AUDIO_DEVICE_OUT_ALL_A2DP);
             mOutDevice = value;
             for (size_t i = 0; i < mEffectChains.size(); i++) {
                 mEffectChains[i]->setDevice_l(mOutDevice);
@@ -4392,7 +4406,7 @@
         sq->push(FastMixerStateQueue::BLOCK_UNTIL_PUSHED);
     }
 
-    return reconfig;
+    return reconfig || a2dpDeviceChanged;
 }
 
 
@@ -4832,6 +4846,7 @@
                                                               status_t& status)
 {
     bool reconfig = false;
+    bool a2dpDeviceChanged = false;
 
     status = NO_ERROR;
 
@@ -4841,6 +4856,8 @@
         // forward device change to effects that have requested to be
         // aware of attached audio device.
         if (value != AUDIO_DEVICE_NONE) {
+            a2dpDeviceChanged =
+                    (mOutDevice & AUDIO_DEVICE_OUT_ALL_A2DP) != (value & AUDIO_DEVICE_OUT_ALL_A2DP);
             mOutDevice = value;
             for (size_t i = 0; i < mEffectChains.size(); i++) {
                 mEffectChains[i]->setDevice_l(mOutDevice);
@@ -4873,7 +4890,7 @@
         }
     }
 
-    return reconfig;
+    return reconfig || a2dpDeviceChanged;
 }
 
 uint32_t AudioFlinger::DirectOutputThread::activeSleepTimeUs() const