From 616bd934f651f66f64b260162f5e84577a3eacc7 Mon Sep 17 00:00:00 2001
From: Marvin Ramin <marvinramin@google.com>
Date: Mon, 27 Apr 2020 17:55:31 +0200
Subject: [PATCH] Audio: Add CEC volume feature callback

Register a listener to HdmiControlManager to get notified when the state
of the HDMI CEC volume control feature changes.

Disabling the CEC volume control feature results in AudioService no
longer attempting to change volume via HDMI CEC.

Test: turn off CEC from Settings, verify CEC messages not sent
Bug: 152018314

Change-Id: I4be3632482fe7dc7fe8e1ad89414ea365fe459df
---
 .../android/server/audio/AudioService.java    | 36 ++++++++++++++++---
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 36272278e0e4a..bbc24eaa63c76 100755
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -920,6 +920,8 @@ public class AudioService extends IAudioService.Stub
                 if (mHdmiManager != null) {
                     mHdmiManager.addHdmiControlStatusChangeListener(
                             mHdmiControlStatusChangeListenerCallback);
+                    mHdmiManager.addHdmiCecVolumeControlFeatureListener(mContext.getMainExecutor(),
+                            mMyHdmiCecVolumeControlFeatureListener);
                 }
                 mHdmiTvClient = mHdmiManager.getTvClient();
                 if (mHdmiTvClient != null) {
@@ -2248,6 +2250,7 @@ public class AudioService extends IAudioService.Stub
                 if (mHdmiManager != null) {
                     // mHdmiCecSink true => mHdmiPlaybackClient != null
                     if (mHdmiCecSink
+                            && mHdmiCecVolumeControlEnabled
                             && streamTypeAlias == AudioSystem.STREAM_MUSIC
                             // vol change on a full volume device
                             && isFullVolumeDevice(device)) {
@@ -2320,7 +2323,8 @@ public class AudioService extends IAudioService.Stub
     @GuardedBy("mHdmiClientLock")
     private void maybeSendSystemAudioStatusCommand(boolean isMuteAdjust) {
         if (mHdmiAudioSystemClient == null
-                || !mHdmiSystemAudioSupported) {
+                || !mHdmiSystemAudioSupported
+                || !mHdmiCecVolumeControlEnabled) {
             return;
         }
 
@@ -2340,7 +2344,8 @@ public class AudioService extends IAudioService.Stub
                     || mHdmiTvClient == null
                     || oldVolume == newVolume
                     || (flags & AudioManager.FLAG_HDMI_SYSTEM_AUDIO_VOLUME) != 0
-                    || !mHdmiSystemAudioSupported) {
+                    || !mHdmiSystemAudioSupported
+                    || !mHdmiCecVolumeControlEnabled) {
                 return;
             }
             final long token = Binder.clearCallingIdentity();
@@ -2940,16 +2945,18 @@ public class AudioService extends IAudioService.Stub
         mVolumeController.postVolumeChanged(streamType, flags);
     }
 
-    // If Hdmi-CEC system audio mode is on and we are a TV panel, never show volume bar.
+    // Don't show volume UI when:
+    //  - Hdmi-CEC system audio mode is on and we are a TV panel
+    //  - CEC volume control enabled on a set-top box
     private int updateFlagsForTvPlatform(int flags) {
         synchronized (mHdmiClientLock) {
-            if (mHdmiTvClient != null && mHdmiSystemAudioSupported) {
+            if ((mHdmiTvClient != null && mHdmiSystemAudioSupported && mHdmiCecVolumeControlEnabled)
+                    || (mHdmiPlaybackClient != null && mHdmiCecVolumeControlEnabled)) {
                 flags &= ~AudioManager.FLAG_SHOW_UI;
             }
         }
         return flags;
     }
-
     // UI update and Broadcast Intent
     private void sendMasterMuteUpdate(boolean muted, int flags) {
         mVolumeController.postMasterMuteChanged(updateFlagsForTvPlatform(flags));
@@ -7141,9 +7148,21 @@ public class AudioService extends IAudioService.Stub
         }
     };
 
+    private class MyHdmiCecVolumeControlFeatureListener
+            implements HdmiControlManager.HdmiCecVolumeControlFeatureListener {
+        public void onHdmiCecVolumeControlFeature(boolean enabled) {
+            synchronized (mHdmiClientLock) {
+                if (mHdmiManager == null) return;
+                mHdmiCecVolumeControlEnabled = enabled;
+            }
+        }
+    };
+
     private final Object mHdmiClientLock = new Object();
 
     // If HDMI-CEC system audio is supported
+    // Note that for CEC volume commands mHdmiCecVolumeControlEnabled will play a role on volume
+    // commands
     private boolean mHdmiSystemAudioSupported = false;
     // Set only when device is tv.
     @GuardedBy("mHdmiClientLock")
@@ -7161,10 +7180,16 @@ public class AudioService extends IAudioService.Stub
     // Set only when device is an audio system.
     @GuardedBy("mHdmiClientLock")
     private HdmiAudioSystemClient mHdmiAudioSystemClient;
+    // True when volume control over HDMI CEC is used when CEC is enabled (meaningless otherwise)
+    @GuardedBy("mHdmiClientLock")
+    private boolean mHdmiCecVolumeControlEnabled;
 
     private MyHdmiControlStatusChangeListenerCallback mHdmiControlStatusChangeListenerCallback =
             new MyHdmiControlStatusChangeListenerCallback();
 
+    private MyHdmiCecVolumeControlFeatureListener mMyHdmiCecVolumeControlFeatureListener =
+            new MyHdmiCecVolumeControlFeatureListener();
+
     @Override
     public int setHdmiSystemAudioSupported(boolean on) {
         int device = AudioSystem.DEVICE_NONE;
@@ -7403,6 +7428,7 @@ public class AudioService extends IAudioService.Stub
         pw.print("  mHdmiPlaybackClient="); pw.println(mHdmiPlaybackClient);
         pw.print("  mHdmiTvClient="); pw.println(mHdmiTvClient);
         pw.print("  mHdmiSystemAudioSupported="); pw.println(mHdmiSystemAudioSupported);
+        pw.print("  mHdmiCecVolumeControlEnabled="); pw.println(mHdmiCecVolumeControlEnabled);
         pw.print("  mIsCallScreeningModeSupported="); pw.println(mIsCallScreeningModeSupported);
         pw.print("  mic mute FromSwitch=" + mMicMuteFromSwitch
                         + " FromRestrictions=" + mMicMuteFromRestrictions