From 1d1884405bf186828c46cba7581cd0d8963e8eb8 Mon Sep 17 00:00:00 2001
From: Sharad Sangle <assangle@codeaurora.org>
Date: Tue, 9 May 2017 16:05:40 +0530
Subject: [PATCH] AudioService: Don't honour SCO ON request if SCO is not
 connected

Usecase:
1. Pair and connect BT headset supporting HFP.
2. Make VOIP calls using application that calls
   setBluetoothScoOn(true) before SCO is actually connected.

Failure:
No audio / ANR are observed on connecting and disconnecting BT headset
during VOIP call.

Rootcause:
On BT connection during VOIP call, app is calling startBluetoothSco()
to setup BT SCO connection. Even before remote BT device SCO connection
establishment(which is taking around 4 secs in issue case), VOIP app
is calling force SCO routing using setBluetoothScoOn() API. This will
result audio modules to force route VOIP call to BT SCO, which results
audio failure/side effects as BT driver return failures. As SCO routing
retry continues several iterations (because of connection delays), this
results ADSP render buffer full followed by improper behavior.

Fix:
Check if SCO connection is establisted before honouring the
setBluetoothScoOn request, if SCO is not connected then
do not process SCO connection.
Only modify internal state when calls to setBluetoothScoOn() are from
system component
Inform audio HAL of SCO audio state via setParameters.

Test: 1. Pair and connect BT headset supporting HFP
      2. Make VOIP calls using application that calls
         setBluetoothScoOn(true) before SCO is actually connected.

Bug: 62051216
Bug: 63740200
Change-Id: Iab8e83613e21831abf5502a0268b1c4f89d6bba5
---
 .../android/server/audio/AudioService.java    | 26 ++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 11d0470ee8e5a..3c1f2d42707a6 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -461,6 +461,8 @@ public class AudioService extends IAudioService.Stub
 
     // Forced device usage for communications
     private int mForcedUseForComm;
+    private int mForcedUseForCommExt; // External state returned by getters: always consistent
+                                      // with requests by setters
 
     // List of binder death handlers for setMode() client processes.
     // The last process to have called setMode() is at the top of the list.
@@ -2890,13 +2892,14 @@ public class AudioService extends IAudioService.Stub
             mForcedUseForComm = AudioSystem.FORCE_NONE;
         }
 
+        mForcedUseForCommExt = mForcedUseForComm;
         sendMsg(mAudioHandler, MSG_SET_FORCE_USE, SENDMSG_QUEUE,
                 AudioSystem.FOR_COMMUNICATION, mForcedUseForComm, eventSource, 0);
     }
 
     /** @see AudioManager#isSpeakerphoneOn() */
     public boolean isSpeakerphoneOn() {
-        return (mForcedUseForComm == AudioSystem.FORCE_SPEAKER);
+        return (mForcedUseForCommExt == AudioSystem.FORCE_SPEAKER);
     }
 
     /** @see AudioManager#setBluetoothScoOn(boolean) */
@@ -2904,6 +2907,13 @@ public class AudioService extends IAudioService.Stub
         if (!checkAudioSettingsPermission("setBluetoothScoOn()")) {
             return;
         }
+
+        // Only enable calls from system components
+        if (Binder.getCallingUid() >= FIRST_APPLICATION_UID) {
+            mForcedUseForCommExt = on ? AudioSystem.FORCE_BT_SCO : AudioSystem.FORCE_NONE;
+            return;
+        }
+
         // for logging only
         final String eventSource = new StringBuilder("setBluetoothScoOn(").append(on)
                 .append(") from u/pid:").append(Binder.getCallingUid()).append("/")
@@ -2913,11 +2923,21 @@ public class AudioService extends IAudioService.Stub
 
     public void setBluetoothScoOnInt(boolean on, String eventSource) {
         if (on) {
+            // do not accept SCO ON if SCO audio is not connected
+            synchronized(mScoClients) {
+                if ((mBluetoothHeadset != null) &&
+                    (mBluetoothHeadset.getAudioState(mBluetoothHeadsetDevice)
+                             != BluetoothHeadset.STATE_AUDIO_CONNECTED)) {
+                    mForcedUseForCommExt = AudioSystem.FORCE_BT_SCO;
+                    return;
+                }
+            }
             mForcedUseForComm = AudioSystem.FORCE_BT_SCO;
         } else if (mForcedUseForComm == AudioSystem.FORCE_BT_SCO) {
             mForcedUseForComm = AudioSystem.FORCE_NONE;
         }
-
+        mForcedUseForCommExt = mForcedUseForComm;
+        AudioSystem.setParameters("BT_SCO="+ (on ? "on" : "off"));
         sendMsg(mAudioHandler, MSG_SET_FORCE_USE, SENDMSG_QUEUE,
                 AudioSystem.FOR_COMMUNICATION, mForcedUseForComm, eventSource, 0);
         sendMsg(mAudioHandler, MSG_SET_FORCE_USE, SENDMSG_QUEUE,
@@ -2926,7 +2946,7 @@ public class AudioService extends IAudioService.Stub
 
     /** @see AudioManager#isBluetoothScoOn() */
     public boolean isBluetoothScoOn() {
-        return (mForcedUseForComm == AudioSystem.FORCE_BT_SCO);
+        return (mForcedUseForCommExt == AudioSystem.FORCE_BT_SCO);
     }
 
     /** @see AudioManager#setBluetoothA2dpOn(boolean) */