AudioFlinger: Prevent FastMixer for A2DP sink
Also avoids issues with FastMixer and BT suspend.
Test: BT with Play Movies
Bug: 34335167
Bug: 35166960
Bug: 35384619
Change-Id: Ie1bfaf2d09b7cfe6b86a1d26fc1d5fdabf82c020
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 795e009..9e4f1a2 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -3578,9 +3578,17 @@
break;
case FastMixer_Static:
case FastMixer_Dynamic:
- initFastMixer = mFrameCount < mNormalFrameCount;
+ // FastMixer was designed to operate with a HAL that pulls at a regular rate,
+ // where the period is less than an experimentally determined threshold that can be
+ // scheduled reliably with CFS. However, the BT A2DP HAL is
+ // bursty (does not pull at a regular rate) and so cannot operate with FastMixer.
+ initFastMixer = mFrameCount < mNormalFrameCount
+ && (mOutDevice & AUDIO_DEVICE_OUT_ALL_A2DP) == 0;
break;
}
+ ALOGW_IF(initFastMixer == false && mFrameCount < mNormalFrameCount,
+ "FastMixer is preferred for this sink as frameCount %zu is less than threshold %zu",
+ mFrameCount, mNormalFrameCount);
if (initFastMixer) {
audio_format_t fastMixerFormat;
if (mMixerBufferEnabled && mEffectBufferEnabled) {