| commit | 51fbaedea1d590466d3777f76ccb82015f5e00a8 | [log] [tgz] |
|---|---|---|
| author | Markus Schmidt <shimodax@gmail.com> | Mon Dec 17 18:30:07 2012 +0100 |
| committer | Jackeagle <jackeagle102@gmail.com> | Thu May 11 08:59:38 2017 -0400 |
| tree | 27e37f15ad0134c9179675742af508e527d9df54 | |
| parent | e24c8c7a7690696c9422baf1876ce8ad169d348b [diff] |
Bluetooth losing HF connection to car-kit after 5 seconds This patch adresses a change in bluetooth which causes a possible loss of connection within 5 seconds after connecting. This new behavior appeared with android 4.2 (4.1.2 worked fine in this regard). I traced down the disconnects to an BTA_AG_SVC_TOUT_EVT via a timer that checks if a service connection was made within a few seconds. Essentially bta_ag_svc_conn_open() was not called on AT+CMER because android thought the car kit supported 3WAY but the car kit did not set the 3WAY flag via AT commands and did not send AT+CHLD either. Android otoh used the flag obtained by SDP and expected 3WAY behavior and eventually disconnected when AT+CHLD did not arrive. This may be a bordeline case, because in the Bluetooth Specification (page 20), assuming service level initialization via SDP is only mentioned on the HF side while there is no such mention (but could probably be implied) on page 21 for the AG. Fact is however, that the use of SDP features value for peer_features is new since Android 4.2 and breaks existing good behavior on a BMW 2005/E46 car kit (navi professional). This kit never asks for AT+CHLD and never via AT commands suggests it supports 3WAY (although it seems to have the flag set via SDP). Also, having essential behavior (like making the connection or not) depend on circumstances that may be prone to race conditions, may be a good reason to not use the SDP flag also (or at least masking out the 3WAY bit when using it). (An alternative approach could be to hook into bta_ag_timer_cback() and when the timer exipres, but when also AT+CMER has been seen meanwhile, to continue and assume a service level connection without 3WAY, i.e. clearing the 3-way flags but calling bta_ag_svc_conn_open() anyway.) Change-Id: I95dcdc5f46e7af723a655afd3d707764603c96c3 Signed-off-by: Markus Schmidt <shimodax@gmail.com> (cherry picked from commit 662eaddd47bca1de03018fbcbe57ca2bfabaa5ac)
Just build AOSP - Fluoride is there by default.
Instructions for Ubuntu, tested on 15.10 with GCC 5.2.1.
sudo apt-get install libevent-dev
sudo apt-get install ninja-build
or download binary from https://github.com/ninja-build/ninja/releases
Get sha1 of current version from here and then download corresponding executable:
wget -O gn http://storage.googleapis.com/chromium-gn/<gn.sha1>
i.e. if sha1 is "3491f6687bd9f19946035700eb84ce3eed18c5fa" (value from 24 Feb 2016) do
wget -O gn http://storage.googleapis.com/chromium-gn/3491f6687bd9f19946035700eb84ce3eed18c5fa
Then make binary executable and put it on your PATH, i.e.:
chmod a+x ./gn sudo mv ./gn /usr/bin
mkdir ~/fluoride cd ~/fluoride git clone https://android.googlesource.com/platform/system/bt
Then fetch third party dependencies:
cd ~/fluoride/bt mkdir third_party git clone https://github.com/google/googletest.git git clone https://android.googlesource.com/platform/external/libchrome git clone https://android.googlesource.com/platform/external/modp_b64 git clone https://android.googlesource.com/platform/external/tinyxml2
And third party dependencies of third party dependencies:
cd fluoride/bt/third_party/libchrome/base/third_party mkdir valgrind cd valgrind curl https://chromium.googlesource.com/chromium/src/base/+/master/third_party/valgrind/valgrind.h?format=TEXT | base64 -d > valgrind.h curl https://chromium.googlesource.com/chromium/src/base/+/master/third_party/valgrind/memcheck.h?format=TEXT | base64 -d > memcheck.h
Fluoride currently has dependency on some internal Android projects, which also need to be downloaded. This will be removed in future:
cd ~/fluoride git clone https://android.googlesource.com/platform/system/core git clone https://android.googlesource.com/platform/hardware/libhardware git clone https://android.googlesource.com/platform/system/media
We need to configure some paths to make the build successful. Run:
cd ~/fluoride/bt gn args out/Default
This will prompt you to fill the contents of your "out/Default/args.gn" file. Make it look like below. Replace "/home/job" with path to your home directory, and don't use "~" in build arguments:
# Build arguments go here. Examples: # is_component_build = true # is_debug = false # See "gn args <out_dir> --list" for available build arguments. libhw_include_path = "/home/job/fluoride/libhardware/include" core_include_path = "/home/job/fluoride/core/include" audio_include_path = "/home/job/fluoride/media/audio/include"
Then generate your build files by calling
cd ~/fluoride/bt gn gen out/Default
cd ~/fluoride/bt ninja -C out/Default all
This will build all targets (the shared library, executables, tests, etc) and put them in out/Default. To build an individual target, replace "all" with the target of your choice, e.g. ninja -C out/Default net_test_osi.
cd ~/fluoride/bt/out/Default LD_LIBRARY_PATH=./ ./bluetoothtbd -create-ipc-socket=fluoride