audio policy: reduce audio routing commands trafic.
Restrict conditions under which we force a routing change
when an output becomes active to reduce the number of useless
binder calls, context switches and pausing of fast mixer thread.
Bug: 29345846
Change-Id: I492412f0475d6f3d1882af0b85ee0efcfac2b5e5
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index 51066fd..c0bb4e7 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -1167,8 +1167,10 @@
beaconMuteLatency = handleEventForBeacon(STARTING_OUTPUT);
}
+ // force device change if the output is inactive and no audio patch is already present.
// check active before incrementing usage count
- bool force = !outputDesc->isActive();
+ bool force = !outputDesc->isActive() &&
+ (outputDesc->getPatchHandle() == AUDIO_PATCH_HANDLE_NONE);
// increment usage count for this stream on the requested output:
// NOTE that the usage count is the same for duplicated output and hardware output which is
@@ -1188,12 +1190,17 @@
for (size_t i = 0; i < mOutputs.size(); i++) {
sp<AudioOutputDescriptor> desc = mOutputs.valueAt(i);
if (desc != outputDesc) {
- // force a device change if any other output is managed by the same hw
- // module and has a current device selection that differs from selected device.
+ // force a device change if any other output is:
+ // - managed by the same hw module
+ // - has a current device selection that differs from selected device.
+ // - supports currently selected device
+ // - has an active audio patch
// In this case, the audio HAL must receive the new device selection so that it can
// change the device currently selected by the other active output.
if (outputDesc->sharesHwModuleWith(desc) &&
- desc->device() != device) {
+ desc->device() != device &&
+ desc->supportedDevices() & device &&
+ desc->getPatchHandle() != AUDIO_PATCH_HANDLE_NONE) {
force = true;
}
// wait for audio on other active outputs to be presented when starting
