Return-Path: Message-ID: <013e01c8bb99$b4ba5580$6701a8c0@freqonedev> From: "David Stockwell" To: "Marcel Holtmann" , "Johan Hedberg" Cc: "BlueZ development" Subject: Issues with BlueZ v3.31 Object Path Naming Date: Wed, 21 May 2008 18:23:37 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_013B_01C8BB6F.C9229570" List-ID: This is a multi-part message in MIME format. ------=_NextPart_000_013B_01C8BB6F.C9229570 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I have not been chiming in for several weeks, because I have been busy = hacking through code to figure out how bluez is supposed to work, how it = actually works, and issues and incompatibilitites I am struggling with = between bluez (DBus, v3.31) and the CSR BlueLab libraries (v4.0, = compatible with BT2.1).; What fun. In working with my test application, talking with bluez, I have run into = the following and need clarification before proceeding: 1.. What is the path name for the top level Manager interface? Is it = going to be "/org/bluez"? Or is it supposed to be "/"?=20 If you call the DefaultAdapter method with the "/org/bluez" path, it = is resolved to call old_default_adapter in hcid/manager.c, returning a = String representing the old Default Adapter path, or "/org/bluez/hci0"?=20 On the other hand, call the DefaultAdapter method with the "/" path, = it is resolved to call default_adapter in hcid/manager.c, returning an = Object (actually a string representing an object path), representing the = NEW Default Adapter path: "/hci0". However, when returning the Object, = it also throws an error because, somehow, /hci0 was never registered. = (Unregistered object at path '/hci0'). Very bad result.=20 So, what should it be? /org/bluez and /org/bluez/hci0? Or / and = /hci0?=20 And, while we are at it, should we clean up the documentation in = docs/manager-api.txt and docs/adapter-api.txt? Both refer to the "old" = paths. Let me know and I will be happy to "dive in".=20 2.. For what it is worth, the "new" and experimental Adapter methods = ARE registered with path "/hci0", despite the apparent fact that no = object '/hci0' is registered...=20 3.. I had been confused about opening an audio.Control device as = opposed to (or in addition to, or in sequence with) a device under = org.bluez.Adapter, using CreateDevice and CreatePairedDevice. When I = did get things to "work", sort of, CreateDevice would return a device = path name like "/hci0/dev_xx_xx_xx_xx_xx_xx", but on return would fail = with the same "Unregistered object at path" error as above.=20 4.. Along the lines of the last item, it does appear that one must = pair, then one must create an audio "device" using the = org.bluez.audio.Manager CreateDevice method (with path = /org/bluez/audio). Am I correct in this understanding?=20 5.. Yet another question: is the "/org/bluez/audio" path correct, or = will it be changed in the future? When I have used this method, it = returns a device path of "/org/bluez/audio/device0". It is interesting = (and perhaps a bit strange) to use the device address, as opposed to the = device path, to create this pseudo-device to provide the audio services = (Device, Headset, Gateway, Sink, Source, Control). I can quickly submit patches to unify the naming, etc., if you will tell = me your current thinking and roadmap in this area. However, I do not = want to waste my time hacking if you are going in some other direction. David Stockwell ------=_NextPart_000_013B_01C8BB6F.C9229570 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I have not been chiming in for several weeks, because I have been = busy=20 hacking through code to figure out how bluez is supposed to work, how it = actually works, and issues and incompatibilitites I am struggling with = between=20 bluez (DBus, v3.31) and the CSR BlueLab libraries (v4.0, compatible with = BT2.1).; What fun.
 
In working with my test application, talking with bluez, I have run = into=20 the following and need clarification before proceeding:
  1. What is the path name for the top level Manager interface?  = Is it=20 going to be "/org/bluez"? Or is it supposed to be "/"?=20

    If you call the DefaultAdapter method with the "/org/bluez" path, = it is=20 resolved to call old_default_adapter in hcid/manager.c, returning a = String=20 representing the old Default Adapter path, or "/org/bluez/hci0"?=20

    On the other hand, call the DefaultAdapter method with the "/" = path, it=20 is resolved to call default_adapter in hcid/manager.c, returning an = Object=20 (actually a string representing an object path), representing the = NEW=20 Default Adapter path: "/hci0".  However, when returning the = Object, it=20 also throws an error because, somehow, /hci0 was never = registered. =20 (Unregistered object at path '/hci0'). Very bad result.=20

    So, what should it be?  /org/bluez and = /org/bluez/hci0?  Or /=20 and /hci0?=20

    And, while we are at it, should we clean up the documentation in=20 docs/manager-api.txt and docs/adapter-api.txt?  Both refer to = the "old"=20 paths.  Let me know and I will be happy to "dive in". =

  2. For what it is worth, the "new" and experimental Adapter methods = ARE=20 registered with path "/hci0", despite the apparent fact that no object = '/hci0'=20 is registered...=20
  3. I had been confused about opening an audio.Control device as = opposed to=20 (or in addition to, or in sequence with) a device under = org.bluez.Adapter,=20 using CreateDevice and CreatePairedDevice.  When I did get things = to=20 "work", sort of, CreateDevice would return a device path name like=20 "/hci0/dev_xx_xx_xx_xx_xx_xx", but on return would fail with the same=20 "Unregistered object at path" error as above.=20
  4. Along the lines of the last item, it does appear that one must = pair, then=20 one must create an audio "device" using the=20 org.bluez.audio.Manager CreateDevice method (with path=20 /org/bluez/audio).  Am I correct in this understanding?=20
  5. Yet another question: is the "/org/bluez/audio" = path correct, or=20 will it be changed in the future?  When I have used this method, = it=20 returns a device path of "/org/bluez/audio/device0".  It is = interesting=20 (and perhaps a bit strange) to use the device address, as opposed to = the=20 device path, to create this pseudo-device to provide the audio = services=20 (Device, Headset, Gateway, Sink, Source, Control).
I can quickly submit patches to unify the naming, etc., if you = will=20 tell me your current thinking and roadmap in this area.  However, I = do not=20 want to waste my time hacking if you are going in some other = direction.
 
David Stockwell
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