Track volume cleanup

Always read and write track volumes atomically. In most places this was
already being done, but there were a couple places where the left and
right channels were read independently.

Changed constant MAX_GAIN_INT to be a uint32_t instead of a float.
It is always used as a uint32_t in comparisons and assignments.
Use MAX_GAIN_INT in more places.

Now that volume is always accessed atomically, removed the union
and alias for uint16_t volume[2], and kept only volumeLR.

Removed volatile as it's meaningless.

In AudioFlinger, clamp the track volumes read from shared memory
before applying master and stream volume.

Change-Id: If65e2b27e5bc3db5bf75540479843041b58433f0

1 files changed, 0 insertions, 1 deletions

diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 97b2312..7e338de 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -480,7 +480,6 @@ status_t AudioTrack::setVolume(float left, float right)
     mVolume[LEFT] = left;
     mVolume[RIGHT] = right;
 
-    // write must be atomic
     mCblk->volumeLR = (uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000);
 
     return NO_ERROR;