Effect: Configure effect after the buffer is set.

This properly sets ACCUMULATE vs WRITE mode.
Fixes regression due to
commit f1f22e7720456d52dc3cc844a51a21216c7be4e6

Test: YouTube Music, ensure that volume doesn't increase.
Bug: 200228253
Bug: 204489508
Change-Id: Ieb309b4103cf29c8a51818135f9f83c292d7aaed
diff --git a/services/audioflinger/Effects.cpp b/services/audioflinger/Effects.cpp
index b80943e..d09c9f4 100644
--- a/services/audioflinger/Effects.cpp
+++ b/services/audioflinger/Effects.cpp
@@ -953,11 +953,7 @@
     // Auxiliary effect:
     //      accumulates in output buffer: input buffer != output buffer
     // Therefore: accumulate <=> input buffer != output buffer
-    if (mConfig.inputCfg.buffer.raw != mConfig.outputCfg.buffer.raw) {
-        mConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_ACCUMULATE;
-    } else {
-        mConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_WRITE;
-    }
+    mConfig.outputCfg.accessMode = requiredEffectBufferAccessMode();
     mConfig.inputCfg.mask = EFFECT_CONFIG_ALL;
     mConfig.outputCfg.mask = EFFECT_CONFIG_ALL;
     mConfig.inputCfg.buffer.frameCount = callback->frameCount();
@@ -2340,8 +2336,10 @@
         // output buffer, otherwise to chain input buffer
         if (idx_insert == size) {
             if (idx_insert != 0) {
-                mEffects[idx_insert-1]->configure();
-                mEffects[idx_insert-1]->setOutBuffer(mInBuffer);
+                // update channel mask before setting output buffer.
+                mEffects[idx_insert - 1]->configure();
+                mEffects[idx_insert - 1]->setOutBuffer(mInBuffer); // set output buffer
+                mEffects[idx_insert - 1]->updateAccessMode();      // reconfig if neeeded.
             }
             effect->setOutBuffer(mOutBuffer);
         } else {
diff --git a/services/audioflinger/Effects.h b/services/audioflinger/Effects.h
index 389ff7b..9c832c6 100644
--- a/services/audioflinger/Effects.h
+++ b/services/audioflinger/Effects.h
@@ -254,6 +254,13 @@
         return mOutBuffer != 0 ? reinterpret_cast<int16_t*>(mOutBuffer->ptr()) : NULL;
     }
 
+    // Updates the access mode if it is out of date.  May issue a new effect configure.
+    void        updateAccessMode() {
+                    if (requiredEffectBufferAccessMode() != mConfig.outputCfg.accessMode) {
+                        configure();
+                    }
+                }
+
     status_t         setDevices(const AudioDeviceTypeAddrVector &devices);
     status_t         setInputDevice(const AudioDeviceTypeAddr &device);
     status_t         setVolume(uint32_t *left, uint32_t *right, bool controller);
@@ -289,6 +296,11 @@
     status_t stop_l();
     status_t removeEffectFromHal_l();
     status_t sendSetAudioDevicesCommand(const AudioDeviceTypeAddrVector &devices, uint32_t cmdCode);
+    effect_buffer_access_e requiredEffectBufferAccessMode() const {
+        return mConfig.inputCfg.buffer.raw == mConfig.outputCfg.buffer.raw
+                ? EFFECT_BUFFER_ACCESS_WRITE : EFFECT_BUFFER_ACCESS_ACCUMULATE;
+    }
+
 
     effect_config_t     mConfig;    // input and output audio configuration
     sp<EffectHalInterface> mEffectInterface; // Effect module HAL