commit 7ed66a1a879399edf356e54f09d59c1a7ca2d5f7
author Phil Burk <philburk@google.com> Thu Apr 18 13:20:30 2019 -0700
committer Phil Burk <philburk@google.com> Fri Apr 19 19:03:30 2019 +0000
tree 498ea915266ffda87754b03e4b40230e2712ee1d
parent 8263e3519b6801f019e471efe4a6045b7046e4d3

AudioFlinger: allow small requested capacity for FAST path

AudioFlinger used to reject requests for the low latency FAST
path when the capacity was != mPipeFramesP2.
But if the caller requests < mPipeFramesP2 than we can just bump it
up to mPipeFramesP2 because the API allows that.

For example, on Pixel, mPipeFramesP2 is 4096

Bug: 80308183
Test: adb shell input_monitor_callback -pl -b4000 -m1
Test: should see performance mode 12 for LOW_LATENCY
Change-Id: I987067910de3194fb52370d0ea1626cffad6248c

services/audioflinger/Threads.cpp

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 59ced26..711a6dd 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -7454,8 +7454,10 @@
             // we formerly checked for a callback handler (non-0 tid),
             // but that is no longer required for TRANSFER_OBTAIN mode
             //
-            // frame count is not specified, or is exactly the pipe depth
-            ((frameCount == 0) || (frameCount == mPipeFramesP2)) &&
+            // Frame count is not specified (0), or is less than or equal the pipe depth.
+            // It is OK to provide a higher capacity than requested.
+            // We will force it to mPipeFramesP2 below.
+            (frameCount <= mPipeFramesP2) &&
             // PCM data
             audio_is_linear_pcm(format) &&
             // hardware format